Securities registered pursuant to Section 12(g) of the Act: None

This Annual Report on Form 10-K contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended (the “Securities Act”), and Section 21E of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), which statements involve substantial risks and uncertainties. Forward-looking statements generally relate to future events or our future financial or operating performance. In some cases, you can identify forward-looking statements because they contain words such as “may,” “can,” “will,” “would,” “should,” “expects,” “plans,” “anticipates,” “could,” “intends,” “target,” “projects,” “contemplates,” “believes,” “estimates,” “predicts,” “forecasts,” “potential,” or “continue” or the negative of these words or other similar terms or expressions that concern our expectations, strategy, plans or intentions. Forward-looking statements contained in this Annual Report on Form 10-K include, but are not limited to, statements about:

We caution you that the foregoing list may not contain all of the forward-looking statements made in this Annual Report on Form 10-K.

You should not rely upon forward-looking statements as predictions of future events. We have based the forward-looking statements contained in this Annual Report on Form 10-K primarily on our current expectations and projections about future events and trends that we believe may affect our business, results of operations and financial condition. The outcome of the events described in these forward-looking statements is subject to risks, uncertainties and other factors described below in Part II,I, Item 1A, “Risk Factors,” and elsewhere in this Annual Report on Form 10-K. Moreover, we operate in a very competitive and rapidly changing environment. New risks and uncertainties emerge from time to time, and it is not possible for us to predict all risks and uncertainties that could have an impact on the forward-looking statements contained in this Annual Report on Form 10-K. We cannot assure you that the results, events and circumstances reflected in the forward-looking statements will be achieved or occur, and actual results, events or circumstances could differ materially from those described in the forward-looking statements.

The forward-looking statements made in this Annual Report on Form 10-K relate only to events as of the date on which the statements are made. We undertake no obligation to update any forward-looking statements made in this Annual Report on Form 10-K to reflect events or circumstances after the date of this Annual Report on Form 10-K or to reflect new information or the occurrence of unanticipated events, except as required by law. We may not actually achieve the plans, intentions or expectations disclosed in our forward-looking statements, and you should not place undue reliance on our forward-looking statements. Our forward-looking statements do not reflect the potential impact of any future acquisitions, mergers, dispositions, joint ventures or investments we may make.

We aim to deliver the leading customer engagement platform that intelligently orchestrates customer engagement across the entire customer life cycle. Our platform provides developers tools to build, scale, and deploy real-time communications within software applications, while simultaneously offering technology that allows businesses to harness the power of first-party data to improve the experience of their customers. The data that our platform collects can inform every interactioninteractions across the customer journey to achieve more personalized, timely and impactful engagement. This in turn empowers businesses to build productive one-to-one relationships, at scale, through both easy-to-use APIs and extensible software products like Twilio Flex and Twilio Engage. The central pillars of our customer engagement platform, consistent with the new business unit structure referenced above, are described below.

We believe that a personalized, positive customer experience is the best path toa key driver of effective customer engagement and long-term customer loyalty. Our Data & ApplicationsSegment solutions enable businesses to create highly personalized experiences and campaigns across multiple channels using first-party, real-time customer data. They also allow businesses to break down data silos across their organizations and to leverage a single unified source of customer data for their various business teams.

We are a leader inOur goal is to deliver the leading customer engagement platform category. Retaining this position will require both continued innovation and discipline with respect to prioritization and focus.platform. We are concentrating our investments inon the highest-impact product areas for our future, and we intend to pursue the following strategies:

We believe that we compete favorably on the basis of the factors listed above and that none of our competitors currently compete directly with us across all of our product offerings.

Our research and development efforts are focused on building a trusted, comprehensive customer engagement platform while enhancing our existing products and developing new products and features.

Our research and development organization is predominantly built around small development teams. Our small development teams foster greater agility, which enables us to develop new, innovative products and make rapid changes to our infrastructure that increase resiliency and operational efficiency. Our development teams designed and built much of our customer engagement platform, our core platforms stack, as well as our Super Network. These teams continue to focus on the highest impact product areas for our future. future, which includes focusing on continued innovation in the face of rapid technological change and changing industry practices. We are continuing to invest in AI and ML capabilities, which we believe have the potential to enhance both our Communications and Segment offerings, as well as to automate processes and help our business run more efficiently.

As of December 31, 2022,2023, we had 3,5902,563 employees in our research and development organization.

Our Data & Applicationsgo-to-market model for our Communications business has three pillars: self-service developers, ISV partners, and enterprise customers. Developers are able to access our easy-to-configure APIs, extensive self-service documentation and customer support team, to embed our communications products requireinto their applications during an initial free trial period. Customers can then provide their credit card information to make an upfront prepayment that is drawn down as they use our products. ISVs leverage our Communications APIs to build software and services that they can resell to customers across a strategicvarying number of use cases and verticals. Enterprise customers have access to our solutions team to support their businesses across their customer journey.

Our go-to-market model for our Segment business requires a consultative solution-oriented sales model that emphasizes value-based discovery, technical proof of concept, and deep customer relationship building. We are deliberate in developing these skills and customer relationships leveraging the trust and reputation we have built while solving new and broader problems for our customers. Our Data & Applications products are primarily offered on a subscription basis. Our Communications products that are integrated into our Data & Applications products are charged on a usage basis.

Additionally, when such engagement is needed to provide value to our self-serving customers. Our Email solution is offered on a subscription basis.

To make it easy to learn how to use our products, we provide all of our users with comprehensive documentation, how-to guides and tutorials. We supplement and enhance these tools with the participation of our engaged developercustomer community. In addition, we provide support options to address the individualized needs of our customers. All of our customers get free support and system status notifications. Our customers can also engage with the broader Twilio community to resolve issues.

WeFor our Communications products, we generally offer three paid tiers of support with increasing levels of availability and guaranteed response times. Our highest tier plan, intended for our largest customers, includes a dedicateddesignated support engineer, duty manager coverage and quarterly status reviews. Similarly, our subscription products generally feature a base level of customer support plus premium, paid support options. Our support model is global, with 24x7 coverage and support offices located throughout the world, with our larger offices located in the United States, Ireland, Colombia, India, and Singapore.available 24x7. We currently derive an insignificant amount of revenue from fees for customer support.

We also offer professional services which provide in-depth, hands-on, fee-based packages of advisory, software architecture, integration and coding services to existing and prospective customers and partners to optimize their use of the Twilio platform. For our Data & Applications products,Flex and Segment, offerings include services for implementing contactdigital engagement center solutions and customer data platform design. For our other Communications products, offerings include email implementation and deliverability, and configuration and integration of our communications channels.

We rely on a combination of patent, copyright, trademark, trade secret and other intellectual property laws in the United States and other jurisdictions, as well as license agreements, other contractual protections, and internal processes, procedures, and controls, to protect, establish, maintain, and enforce our intellectual property and other proprietary rights technology. We also rely on a number of registered trademarks, applications for trademarks and common law protections afforded to certain unregistered trademarks to protect our brand.

We currently, and will continue to, seek to protect our intellectual property and other proprietary rights by, among other things, implementing, maintaining, and enforcing a policy that requires our employees, independent contractors and certain suppliers involved in developing intellectual property for us or on our behalf to enter into agreements acknowledging that all work product or other forms of intellectual property generated, created, reduced to practice, conceived, or otherwise developed by them on our behalf are owned by us such that we can use the intellectual property they develop for our business purposes.

We believe there is a unique spirit to Twilio, manifested in who we are and how we work together. We value and invest in a positive culture of optimism, innovation, and accountability. Our values, which we call the Twilio Magic, remind us every day who we are at our core and guide how we act and how we make decisions.

Communications play a critical role in solving some of the world’s toughest social challenges. Nonprofits are meeting the increased demand for their support throughFrom empowering people affected by violence with critical resources, to streamlining staff and volunteer coordination, nonprofits leverage communication technology and in doing so are helping moreto help individuals build long term well-being and helpingto help communities recover from humanitarian crises. Through Twilio.org, which is a part of our company and not a separate legal entity, we donate and sell our products at a reduced rate to nonprofits and offer grant funding to help scale these organizations' missions. In 2015, we reserved 1% of Twilio's common stock to fund Twilio.org. As of December 31, 2022, 530,4492023, 442,041 shares of Twilio Class A common stock were set aside for Twilio.org operations.charitable activities. In 2022,2023, over 15,00020,000 active social impact accountscustomers used Twilio products and funding to reach more than 559546 million people worldwide.

Information on our key ESG programs, goals and commitments, and certain metrics can be found in our annual Impact and DEI Report, available on our website at https://investors.twilio.com/governance. Website references throughout this document are provided for convenience only, and the content on the referenced websites is not incorporated by reference into this report. While we believe that our ESG goals align with our long-term growth strategy and financial and operational priorities, they are aspirational and may change, and there can be no assurance that they will be met.

As of December 31, 2022,2023, we had a total of 8,1565,867 employees, including 3,4902,337 employees located outside of the U.S. NoneAlthough we have works council, statutory and/or collective bargaining employee representation obligations in certain countries outside of the U.S., none of our U.S. employees are represented by a labor union with respect to their employment. Employees in certain of our non-U.S. subsidiaries have the benefits of collective bargaining arrangements at the national level. We consider our relations with our employees to be good and have not experienced interruptions of operations or work stoppages due to labor disagreements.

Diversity, EquityWe are committed to embedding and Inclusion

We are committed to delivering a comprehensive compensation and benefits program that provides support for all of our employees’ well-being. We provide competitive compensation and benefits to attract and retain talented employees, including offering market-competitive salaries, equity, andincentive compensation in the caseform of ourbonuses or sales teams, commissions. We generally offer full-time employeescommissions, and equity at the time of hire and through annual equity grants, as well as through an employee stock purchase plan, to foster a strong sense of ownership in and commitment to our long-term success.compensation for certain employees.

We ensure that our compensation is fair for all employees, regardless of classifications, such as race and gender. We routinely run a rigorous statistical analysis to ensure compensation is fair, taking into account factors that should impact pay, like role, level, location, and performance.

Our full-time employees are eligible to receive, subject to the satisfaction of certain eligibility requirements, our comprehensive benefits package that includes medical, dental and vision insurance and life and disability insurance plans. In addition, we provide time off and we maintain a tax-qualified 401(k) retirement plan that provides eligible U.S. employees with an opportunity to save for retirement on a tax-advantaged basis. In 2022,2023, we matched 50% of the first 6% of contributions by plan participants, subject to annual contribution limits set forth in the Internal Revenue Code of 1986, as amended.

In structuring these benefit plans, we seek to provide an aggregate level of benefits that are comparable to those provided by similar companies.

Twilio Inc. was incorporated in Delaware in March 2008. Our principal executive offices are located at 101 Spear Street, Fifth Floor, San Francisco, California 94105, and our telephone number is (415) 390-2337. Our website address is www.twilio.com. Information contained on, or that can be accessed through, our website does not constitute part of this Annual Report on Form 10-K.

Twilio, the Twilio logo and other trademarks or service marks of Twilio appearing in this Annual Report on Form 10-K are the intellectual property of Twilio. Trade names, trademarks and service marks of other companies appearing in this Annual Report on Form 10-K are the intellectual property of their respective holders.

Information about geographic revenue is set forth in Note 1516 of our Notes to Consolidated Financial Statements included in Part II, Item 8, “Financial Statements and Supplementary Data” of this Annual Report on Form 10-K.

Our filings are available to be viewed and downloaded free of charge through our investor relations website after we file them with the Securities and Exchange Commission (“SEC”). Our filings include our Annual Report on Form 10-K, Quarterly Reports on Form 10-Q, our Proxy Statement for our annual meeting of stockholders, Current Reports on Form 8-K and other filings with the SEC. Our investor relations website is located at http://investors.twilio.com. The SEC also maintains an Internet website that contains periodic and current reports, proxy statements and other information about issuers, like us, that file electronically with the SEC. The address of that website is www.sec.gov.

We webcast our earnings calls and certain events we participate in or host with members of the investment community on our investor relations website. Additionally, we provide notifications of news or announcements regarding our financial performance, including SEC filings, investor events, press and earnings releases, and blogs as part of our investor relations website. Further corporate governance information, including our corporate governance guidelines and code of business conduct and ethics, is also available on our investor relations website under the heading “Governance.” The contents of our websites are not intended to be incorporated by reference into this Annual Report on Form 10-K or in any other report or document we file with the SEC, and any references to our websites are intended to be inactive textual references only.

The occurrence of one or more of the foregoing and other factors may cause our results of operations to vary significantly. As such, comparing our operating results on a period-to-period basis may not be meaningful and should not be relied upon as an indication of future performance. In addition, a significant percentage of our operating expenses is fixed in nature and is based on forecasted revenue trends. Accordingly, in the event of a revenue shortfall, we may not be able to mitigate the negative impact on our net income (loss) and margins in the short term. If we fail to meet or exceed the expectations of investors or securities analysts, then the trading price of our Class A common stock could fall substantially, and we could face costly lawsuits, including securities class action suits.

In September of 2022,December 2023, we reduced our workforce by approximately 11%5%, and in February 2023, we reducedafter reducing our workforce by an additionalapproximately 11% and approximately 17%. in September 2022 and February 2023, respectively. While our reductions in force and other efforts to restructure our business were designed to streamline operations, reduce operating costs, improve operating margins, and shiftrealign our selling capacity, to accelerate software sales, we may encounter challenges in the execution of these efforts that could prevent us from recognizing the intended benefits of such efforts or otherwise adversely affect our business, results of operations and financial condition.

As a result of the reductions in force, we have incurred, and may continue to incur, additional costs in the short-term,short term, including cash expenditures for employee transition,transitions, notice period and severance payments, employee benefits and related facilitation costs, as well as non-cash expenditures related to vesting of share-based awards. These additional cash and non-cash expenditures could have the effect of reducing our operating margins. Our reductions in force may result in other unintended consequences, including employee attrition beyond our intended reduction in force, which may also be further exacerbated by the actual or perceived declining value of our equity awards;force; damage to our corporate culture and decreased employee morale among our remaining employees, including as a result of reduced employee perks;employees; diversion of management attention; damage to our reputation as an employer, which could make it more difficult for us to hire new employees in the future; and the loss of institutional knowledge and expertise of departing employees. If we experience any of these adverse consequences, our reductions in force and other restructuring efforts may not achieve or sustain their intended benefits, or the benefits, even if achieved, may not be adequate to meet our long-term profitability and operational expectations, which could adversely affect our business, results of operations and financial condition.

As we continue to identify areas of cost savings and operating efficiencies, we may consider implementing further measures to reduce operating costs and improve operating margins. We may not be successful in implementing such initiatives, including as a result of factors beyond our control. If we are unable to realize the anticipated savings and efficiencies from our reductions in force, other restructuring efforts and future strategic initiatives, our business, results of operations and financial condition could be harmed.

As we announced in February 2023, inIn the first quarter of 2023, we reorganized our business into two business units – Twilio units—Communications and Twilio Data & Applications – Applications—to enable us to develop the organization and systems to successfully operate a multi-product business and to better align our sales resources with customer and market opportunities. In addition, as the business units were created based on how management views and evaluates our business, beginning with the quarter ended June 30, 2023, we changed our operating and reporting segment structure from one reportable segment to two reportable segments and revised our prior period presentation to conform to the new segments. In the fourth quarter of 2023, we modified the organization of our business units by moving Flex and Marketing Campaigns from Data & Applications to Communications, and we subsequently renamed Data & Applications to Segment.

We expect that ourOur business unit reorganization and changes in our segment reporting structure have required, and will continue to require, significant expenditures, and allocation of valuable management resources, and may place significant demands on our operational and financial infrastructure. This could lead to a number of risks, including: actual or perceived disruption of service or reduction in service standards to our customers; the failure to preserve adequate internal controls as we reorganize our general and administrative functions, including our information technology and financial reporting infrastructure; the failure to preserve partnership, sales and other important relationships and to resolve conflicts that may arise; loss of sales as we eliminate certain sales positions, reorganize our sales teams into business units, and focus on leveragingimprove and expand our use of self-service capabilities; failure to develop effective cross-selling motions between the businesses; failure of the business units to drive efficiencies and leverage; diversion of management attention from ongoing business activities and core business objectives in order to manage operational changes; and the failure to maintain our corporate culture, employee morale and productivity, and to retain highly skilled employees due to reductions in our workforce and changes in leadership structure. Because of these and other factors, we cannot predict whether we will

Our revenue grows as customers increase their usage of a product, extend their usage of a product to new applications or adopt a new product that we offer. The majority of our revenue is usage-based and our ability to grow and generate incremental revenue depends, in part, on our ability to maintain and grow our relationships with existing customers and to have them increase their usage of our platform.products. If our customers do not increase their use of our products, then our revenue may decline. The majoritydecline or grow at rates lower than expected. Most of our customers are charged based on their usage of our products. Mostusage-based customers do not have long-term contractual financial commitments to us and, therefore, most of our customers may reduce or cease their use of our products at any time without penalty or termination charges. Our subscription-based customers generally base their contract value on anticipated usage, and if their anticipated levels of usage are not met, they may reduce their contract value or choose not to renew their contract upon its expiration.

Customers may terminate or reduce their use of our products for any number of reasons, including if they are not satisfieddissatisfaction with our products or with the value proposition of our products, or our abilityinability to meet their needs and expectations, or due to their use of competitors’ products. For example,products, macroeconomic conditions, or reductions in their budgets. Additionally, prior instances of disruptions in our cloud communications platform impacted our customers’ ability to use products on our platform for up to several hours at a time. Issues with our products have caused, and may in the future cause, us to incur certain costs associated with offering credits to our affected customers, which have had, and in the future may have, an adverse impact on customer satisfaction and our ability to retain or attract customers.

Additionally, we believe our ability to provide customers with high-quality, effective customer support services at all stages of the process is a crucial component of maintaining customer satisfaction, generating increased customer usage of our products and ultimately retaining customers. Our inability to devote sufficient resourcesIf we are unable to effectively assist our customers, it could adversely affect our ability to retain existing customers and could disincentivize prospective customers from adopting our products. WeThe resources we dedicate to customer service at a particular time may beprove insufficient, such as in the event we are unable to respond quickly enough to accommodate short-term increases in demand for customer support. We also may be unable to modify the nature, scope and delivery of our customer support in order to compete with changes in the support services provided by our competitors. Our sales are highly dependent on our business reputation and on positive recommendations from our customers. Our inabilityIf we are unable to provide high-quality customer support, or if there is a market perception that we do not maintain high-quality customer support, it could erode the trust of current and potential customers and adversely affect our reputation.

Customer usage of our products isdepends on factors generally outside of our control, and thereforeincluding macroeconomic conditions, so it is difficult to accurately predict customers’ usage levels. The loss of customers or reductions in their usage levels of our products may each have a negative impact on our business, results of operations and financial condition. Our Dollar-Based Net Expansion Rate has recently declined as compared to prior periods, and it may continue to decline in the future if customers are not satisfied with our products and related customer service experience, the value proposition of our products or our ability to meet their needs and expectations.expectations, or due to macroeconomic conditions or reductions in customers’ budgets. If a significant number of customers cease using, or reduce their usage of our products, including due to cost-saving measures in the face of macroeconomic uncertainty or changes in the competitive landscape, then we may be required to spend significantly more on sales and marketing than we currently expect in order to maintain or increase revenue from customers. Such additional sales and marketing expenditures could adversely affect our business, results of operations and financial condition.

To grow our business, we must continue to attract new customers in a cost-effective manner, increase revenue from existing customers, and increase gross margins,profits, each of which depends in part on our ability to enhance and improve our existing products, increase adoption and usage of our products, and introducesuccessfully market new products, particularlyincluding products with higher gross margins.margins, in a cost-effective manner. We use a variety of marketing channels to promote our products and platform, such as developer events and developer evangelism, search engine marketing and optimization, regional customer events, email campaigns, billboard advertising and public relations initiatives. If the costs of the marketing channels we use increase, then we may choose to use alternative and less expensive channels, which may not be as effective as the channels we currently use. We have made in the past, and may make in the future, significant expenditures and investments of time and resources in new marketing campaigns and sales motions, and we cannot guarantee that any such investments will lead to wider adoption of our products or to the cost-effective acquisition of additional customers. In addition, new products that we develop may require increasingly sophisticated and more costly sales efforts and result in a longer sales cycle. If we are unable to maintain effective marketing programs, then our ability to efficiently attract new customers could be adversely affected, and we may not be able to attract the number and types of new customers we are seeking.

Historically, a majority of our revenue has been generated as a result of software developers adopting our Communications API products through our self-service model. Our ability to increase our customer base, especially among enterprises, and achieve broader market acceptance of our products will depend, in part, on our ability to effectively organize, focus and train our sales, marketing and other employees. Our ability to convince enterprises to adopt our products will depend, in part, on our ability to attract and retain sales employees with experience selling to enterprises. We believe that there is significant competition for experienced sales professionals with the skills and technical knowledge that we require. Even if we are successful in hiring qualified sales employees, new hires require significant training and experience before they achieve full productivity, particularly for sales efforts targeted at enterprises and new territories. Our recent hires and planned hires may not become as productive as quickly as we expect, and we may encounter difficulties or be unable to hire or retain sufficient numbers of qualified individuals in the future in the markets where we do business. Because we do not have a long history of targeting our sales efforts at enterprises, we cannot predict whether, or to what extent, our sales will increase as we organize and train our sales force or how long it will take for sales employees to become productive.

As we seek to increase the adoption of our products by enterprises, including products like Segment and Engage, which are primarily aimed at complex customer data platform implementations at larger companies, and Flex, which is primarily aimed at complex contact center implementations at larger companies, we expect to incur higher costs and longer sales cycles. In the enterprise market segment, the decision to adopt our products may require the approval of multiple technical and business decision makers, including legal, security, compliance, procurement, operations and information technology (“IT”). In addition, while enterprise customers may quickly deploy our products on a limited basis, before they will commit to deploying our products at scale, they often require extensive education about our products and significant customer support time and also engage in protracted pricing and contract negotiations, which may be exacerbated by changing inflationary pressure and reduced IT budgets and may result in higher costs and longer sales cycles. In addition, sales cycles for enterprises are inherently more complex and less predictable than the sales through our self-service model, and some enterprise customers may not use our products enough to generate revenue that justifies the cost to obtain such customers. These complex and resource-intensive sales efforts could place additional strain on our product and engineering resources. Further, enterprises, including some of our

Our ability to attract new customers and increase revenue from existing customers depends in large part on our ability to enhance and improve our existing products and to introduce compelling new products that reflect the changing nature of our markets, technology, industry standards, and customer needs and preferences. The success of any enhancements or new products we introduce depends on several factors, including timely completion, adequate quality testing, actual performance quality, market-accepted pricing levels and overall market acceptance. Enhancements and new products that we develop may not be introduced in a timely or cost-effective manner, may contain errors or defects, may require reworking features and capabilities, may have interoperability difficulties with our platform or other products or may not achieve the broad market acceptance necessary to generate significant revenue or increase our gross profits. Furthermore, our ability to increase the usage of our products depends, in part, on the development of new use cases for our products, which is typically driven by our developer community and may be outside of our control.

The markets for our products, including the market for communications in general and cloud communications in particular, are subject to rapid technological change, evolving industry standards, and changing regulations, as well as changing customer needs, requirements and preferences. These are all uncertain and we cannot predict the consequences, effects, or introduction of new, disruptive, emerging technologies or the manner and pace at which our markets develop over time, and our ability to compete in these markets depends on predicting and adapting to these changing circumstances. The success of our business will depend, in part, on our ability to adapt and respond effectively to these changes on a timely basis, and anticipating these factors requires that we allocate significant resources without any guarantee that any such investments and efforts will result in initial or enhanced adoption of our products in the marketplace. For example, with the development of next-generation solutions that utilize new and advanced features, including AI and ML, we expect to commit significant resources to developing new products and enhancements incorporating AI and ML, and there is no guarantee that our investments and efforts will result in wider adoption of our products in the marketplace. If new technologies emerge that are able to deliver competitive products and services at lower prices, more efficiently, more conveniently or more securely or if new products are introduced into the market that could render our existing products obsolete, such technologies and products could adversely impact our ability to compete effectively and may lead to customers reducing or terminating their usage of our products. For example, if user authentication practices evolve to reduce or eliminate the use of one-time passwords, our revenue could be adversely affected.

Additionally, the success of our existing products and any new products we introduce depends, in part, on our ability to integrate them with third-party products used by us or our customers. The providers of such third-party products may modify the features, functionality, pricing, and other terms and conditions with respect to such products in a manner adverse to us and to our customers that use such third-party products in connection with our products. If we are unable to maintain the integrations between our products and such third-party products, our ability to meet the needs and expectations of our current and prospective customers could be adversely affected, which could adversely affect our business. Our platform must integrate with and leverage a variety of infrastructure, network, hardware, mobile and software platforms and technologies, and we need to continuously modify and enhance our products and platform continuesto adapt to changes and innovation in these technologies. For

The marketmarkets for our products and platform continuescontinue to evolve, which makes our business and future prospects difficult to evaluate. We believe that our revenue currently constitutes a significant portion of the total revenue in the market,If current and therefore, we believe that our future success will depend in large part on the growth, if any, and evolution of this market. If developers and organizationsprospective customers do not recognize the need for and benefits of our products and platform, they may decide to adopt alternative products and services to satisfy some portion of their business needs. In order to grow our business and extend our market position, we intend to focus on educating developers and other potential customersenterprises about the benefits of our products and platform, expanding and improving the functionality of our products and bringing new technologies to market to increase market acceptance and use of our platform. Our growth will depend, in part, on our ability to leverage more ofexpand the markets that our self-service capability for developers that do not need direct account coverage. We will also continue to prioritize accelerating software sales, which could have an impact on our results of operations.products address. Our ability to expand the market that our products and platform addressdo so depends upon a number of factors, including the cost, performance and perceived value associated with such products and platform. The marketmarkets for our products and platform could fail to grow significantly, or at all, or there could be a reduction in demand for our products as a result of any number of factors, including a lack of developercustomer acceptance, technological challenges, competing products and services, decreases in spending by current and prospective customers, weakening economicmacroeconomic conditions, including due to labor shortages, supply chain disruptions and inflationary pressures and other causes. If our market doesthese markets do not experience significant growth or demand for our products decreases, then our business, results of operations and financial condition could be adversely affected.

The marketmarkets for customer engagement platform isour products are rapidly evolving, significantly fragmented and highly competitive, with relatively low barriers to entry in some segments. The principal competitive factors in our market include completeness of offering, credibility with customers, global reach, ease of integration and programmability, product features, platform scalability, reliability, deliverability, security and performance, brand awareness and reputation, the strength of sales and marketing efforts, customer support, as well asand the cost of deploying and using our products. In our Communications business, our competitors are primarily (i) CPaaS companies that offer communications products and applications, (ii) other software companies that compete with portions of our communications product line, and (iii) regional network service providers that offer limited developer functionality on top of their own physical infrastructure, (ii) CPaaS companies that offer communications products and applications, and (iii) other software companies that compete with portions of our communications product line.infrastructure. In our Data & ApplicationsSegment business, our competitors are primarily (i) legacy on-premises vendors, (ii) SaaS companies and marketing cloud platform vendors that offer bundled applications and platforms, and (iii)(ii) CRM and customer experience vendors and (iii) standalone customer data platform vendors.

Some of our competitors and potential competitors are larger and have greater name recognition, longer operating histories, more established customer relationships, larger budgets, lower operating costs, and significantly greater resources than we do. As a result, our competitors may be able to respond more quickly and effectively than we can to new or changing opportunities, technologies, standards, customer requirements or changing economic conditions. Our competitors may also offer products or services that address one or a limited number of functions at lower prices, with greater depth than our products or in different geographies. Our current and potential competitors may develop and market new products and services with comparable functionality to our products, and this could lead to us having to decrease prices in order to remain competitive.

With the introduction of new products and services and new market entrants, we expect competition to intensify in the future. As we expand the scope of our products, we may face additional competition and, in some cases, may find our products in competition with those of our customers, which could cause them to replace our products with competitive offerings. If one or more of our competitors were to merge or partner with another of our competitors or our suppliers, the change in the competitive landscape could also adversely affect our ability to compete effectively. For example, certain of our competitors have engaged in acquisition activity and we expect that our competitors will continue to evaluate the acquisition of companies and technologies that could increase competition with our products in the future. In addition, some of our competitors have lower list prices than us, which may be attractive to certain customers even if those products have different or lesser functionality. Pricing pressures and increased competition generally could result in reduced revenue, reduced margins, increased losses or the failure of our products to achieve or maintain widespread market acceptance, any of which could harm our business, results of operations and financial condition.

Our business, results of operations and financial condition also depends, in part, on our ability to establish and maintain relationships through resellers, distributors, and strategic partners. A portion of our revenue is derived from sales made by these partners and any one of them may later decide to sell their own products or those of third parties that may be competitive with our products. A loss or reduction in sales of our products through these third-party intermediaries could adversely affect our revenue and other results of operations.

We have incurred net losses in each year since our inception, including net losses of $1.0 billion, $1.3 billion $949.9 million and $491.0$949.9 million in the years ended December 31, 2023, 2022 2021 and 2020,2021, respectively. We had an accumulated deficit of $3.4$5.1 billion as of December 31, 2022.2023. We will need to generate and sustain increased revenue levels, and manage our operating expenses, in future periods to become profitable and achieve our stated profitability goals and, even if we do, we may not be able to maintain or increase our level of profitability. We expect to continue to expend substantial financial and other resources on, among other things: investments in our engineering team; improvements in security and data protection; the development of new products, features and functionality and enhancements to our platform; sales and marketing, including the continued expansion of our direct sales organization and marketing programs, especially for enterprises, organizations outside of the United States, and programs directed at increasing our brand awareness among developers, as well expansion of our self-service capabilities;marketing; expansion of our operations and infrastructure, both domestically and internationally; and general administration, including legal, accounting and other expenses related to being a public company. Our efforts to grow our business may be more costly than we expect, and we may not be able to increase our revenue enough to offset our increasedassociated operating expenses. We may incur significant losses in the future for a number of reasons, including the other risks described herein, and unforeseen expenses, difficulties, complications and delays and other unknown events. If we are unable to achieve and sustain profitability, or if we incur significant losses, the value of our business and Class A common stock may significantly decrease.

Our future performance depends on the continued services and contributions of highly skilled personnel, including our senior management and other key employees, to execute on our business plan, to develop our products and platform, to deliver our products to customers, to attract and retain customers and to identify and pursue opportunities to expand our business. We believe that there is, and will continue to be, intense competition for highly skilled management, technical, sales and other employees with experience in our industry. In addition, we have conducted reductions in force and experienced and may continue to experience high levels of employee attrition, which could significantly delay or prevent the achievement of our business objectives, and any resulting influx of new employees may require us to expend time, attention and resources to recruit and retain employees, restructure parts of our organization and train and integrate new personnel. We have focused our hiring efforts on areas such as Segment, Engage and Flex, and we have frozen the vast majority of new hires and backfills outside of these core areas. If we fail to effectively manage attrition, and to hire, integrate and adequately incentivize our personnel, our efficiency and ability to meet our operational and growth targets, as well as our corporate culture, employee morale, productivity and retention, could suffer, and our business and operating results would be adversely impacted.

Additionally, loss of services of senior management or other key employees could significantly delay or prevent the achievement of our development and strategic objectives. In particular, we depend to a considerable degree on the vision, skills, experience and effort ofJanuary 2024, our co-founder, andJeff Lawson, resigned as Chief Executive Officer Jeff Lawson.and as a member of our board of directors, and Khozema Shipchandler, our former President, Twilio Communications, was appointed as Chief Executive Officer and as a member of our board of directors. We will incur various expenses in connection with the transition and we may face challenges in connection with the transition, such as potential changes to our strategy, corporate culture, and other changes in our management structure or roles. Any of our executive officers may terminate employment with us at any time with no advance notice. We have experienced, and may continue to experience, high attrition among our senior management team and key employees. The replacement of any of our senior management or other key employees will involve significant time and costs, and any loss of services of any such key employee for any reason could significantly delay or prevent the achievement of our business objectives and could adversely affect our business, results of operations and financial condition.

The labor market for our business is subject to external factors that are beyond our control, including our industry’s highly competitive market for skilled workers and leaders, inflation, effects that the COVID-19 pandemic has had on the labor market, and workforce participation rates.leaders. We must provide competitive compensation packages and a high-quality work environment to hire, retain and motivate employees. Volatility in, or the actual or perceived lack of performance of, our stock price may affect our ability to attract, motivate and retain key employees. In September 2022, February 2023 and FebruaryDecember 2023, we implemented reductions in force, which may have an impact on our ability to hire, retain and motivate employees. If we are unable to retain and motivate our existing employees and attract qualified employees to fill key positions, we may be unable to manage our business effectively, including the development, marketing and sale of our products, which could adversely affect our business, results of operations and financial condition.

We believe that maintaining and enhancing the “Twilio” brand identity and increasing market awareness of our company and products, particularly among developers and enterprises, is critical to achieving widespread acceptance of our platform, to strengthenstrengthening our relationships with our existing customers and to our ability to attract new customers. The successful promotion of our brand will depend largely on our continued marketing efforts, our ability to continue to offer high-quality products, and our ability to successfully differentiate our products and platform from competing products and services. Our brand promotion and thought leadership activities may not be successful or yield increased revenue. In addition, independent industry analysts often provide reviews of our products and competing products and services, which may significantly influence the perception of our products in the marketplace. If these reviews are negative or not as strong as reviews of our competitors’ products and services, then our brand may be harmed.

The promotion of our brand also requires us to make substantial expenditures, and we anticipate that these expenditures will increase as our market becomesmarkets become more competitive and as we expand into new markets. To the extent that these activities

We currently interconnect with fixed and mobile network service providers around the world to enable the use by our customers of our products over their networks. Although we are in the process of acquiring authorization in many countries for direct access to phone numbers and for the provision of voice and messaging services on the networks of fixed and mobile network service providers, we expect that we will continue to rely on network service providers for these services. Where we do not have direct access to phone numbers, our reliance on network service providers has reduced our operating flexibility, ability to make timely service changes and control quality of service. In addition, the fees that we are charged by network service providers may change daily or weekly and we can be subject to the imposition of additional fees, penalties, or other administrative or technical requirements, and even service interruption, due to regulatory, competitive, or other industry related changes over which we have little to no control. We typically do not change our customers’ pricing as rapidly and, as a result, such fee increases could adversely affect our business and results of operations.

For example, in recent years, multiple major U.S. mobile carriers have introduced Application to Person (“A2P”)A2P SMS service offerings that added a new fee for A2P SMS messages delivered to their respective subscribers, and, from time-to-time,time to time, other U.S. mobile carriers have added similar fees. While we have historically responded to these types of fee increases through a combination of further negotiating efforts with our network service providers, absorbing the increased costs or changing our pricespassing the fees through to customers, there is no guarantee that we will continue to be able to respond in these ways in the future without a material negative impact to our business. In the case of these new carriers’ A2P SMS fees, after a short phase-in period where we absorbed the fees, we began on May 1, 2021 to pass these fees directly through to our customers who are sending SMS

Furthermore, many of these network service providers do not have long-term committed contracts with us and may interrupt services or terminate their agreements with us without notice. If a significant portion of our network service providers stop providing us with access to their infrastructure, fail to provide these services to us on a cost-effective basis, cease operations, or otherwise terminate these services, the delay caused by qualifying and switching to other network service providers could be time consuming and costly and could adversely affect our business, results of operations and financial condition. Further, if problems occur with our network service providers, it may cause errors, service outages, or poor-quality communications on our products, and we could encounter difficulty identifying the source of the problem. The occurrence of errors, service outages, or poor-quality communications on our products, whether caused by our platform or a network service provider, may result in the loss of our existing customers or the delay of adoption of our products by potential customers and may adversely affect our business, results of operations and financial condition.

Further, we sometimes access network services through intermediaries who have direct access to network service providers. Although we are in the process of securing direct connections with network service providers in many countries, we expect that we will continue to rely on intermediaries for these services for some period of time. These intermediaries sometimes have offerings that directly compete with our products and may stop providing services to us on a cost-effective basis. If a significant portion of these intermediaries stop providing services or stop providing services on a cost-effective basis, our business could be adversely affected.

We also interconnect with internet service providers around the world to enable the use of our email products by our customers, and we expect that we willto continue to rely on internet service providers for network connectivity going forward. Our reliance on internet service providers reduces our control over quality of service and exposes us to potential service outages and rate fluctuations. The occurrence of poor-quality of service or service outages on our products may result in the loss of our existing customers or the delay of adoption of our products by potential customers and may adversely affect our business, results of operations and financial condition. Similarly, if a significant portion of our internet service providers stop providing us with access to their network infrastructure, fail to provide access on a cost-effective basis, cease operations, or otherwise terminate access, the delay caused by qualifying and switching to other internet service providers could be time consuming and costly and could adversely affect our business, results of operations, and financial condition.

For certain of our products, we primarily charge our customers based on their useusage of such products (“usage-based pricing”).products. One of the challenges of ourthis usage-based pricing model is the variability of the fees that we pay to network service providers over whose networks we transmit communications. Such network fees can vary daily or weekly and are affected by volume and other factors that may be outside of our control, and which are difficult to predict. This can result in us incurring increased costs that we may be unable or unwilling to pass through to our customers, which could adversely impact our business, results of operations and financial condition. If we elect to pass through increased fees to our customers, it could adversely affect our relationship with our customers and our customers may look for lower cost alternatives.

We adjust the pricing models for our products from time to time and expect that we may needwill continue to changedo so. Many of our usage-based customers enter into contracts with negotiated pricing, model from timeand our subscription customers are also subject to time. In the past, we have at times reduced our prices either for individual customers in connection with long-term agreements or for a particular product. Further, asnegotiated pricing. As competitors introduce new products or services that compete with ours or reduce their prices, we may be unable to attract new customers or retain existing customers based on our historical pricing. AsIf we expand internationally, we also must determine the appropriate price to enable us to compete effectively internationally. Moreover, enterprises may demand substantial price concessions. In addition, if the mix of products sold changes, including for a shift to IP-based products, then we may need to, or choose to, revise our pricing. As a result, in the future we may beare required or choose to reduce our prices, or change our pricing models, whichit could adversely affect our business, results of operations and financial condition.

We are continuing to expand our international operations to increase our revenue from customers outside of the United States as part of our growth strategy. In the years ended December 31, 2023, 2022 and 2021, we derived 34%, 34% and 32% of our revenue

In addition, we will face risks in doing business internationally that could adversely affect our business, including:

Also, due to costs from our international expansion effortsoperations and network service provider fees outside of the United States, which generally are higher than domestic rates, our Communications gross margin for international customers is typically lower than our Communications gross margin for domestic customers. As a result, our Communications gross margin has been, and may continue to be, adversely impacted as we expandby our operations and customer base worldwide.international operations. Our failure to manage any of these risks successfully could harm our international operations, and adversely affect our business, results of operations and financial condition.

In the years ended December 31, 2023, 2022 2021 and 2020,2021, our 10 largest Active Customer Accounts generated an aggregate of 12%10%, 11%12% and 14%11% of our revenue, respectively. If any of these customers, or other large customers, do not continue to use our products, use fewer of our products, or use our products in a more limited capacity, or not at all, our business, results of operations and financial condition could be adversely affected. Additionally, the usage of our products by customers that do not have long-term contracts with us may change between periods. Those with no long-term contract with us may reduce or fully terminate their usage of our products at any time without notice, penalty or termination charges, which may adversely impact our results of operations.

We have acquired and invested in businesses and technologies that are complementary to our business through acquisitions, partnerships or investments, and we expect to continue to selectively evaluate strategic opportunities in the future. There can be no assurances that our businesses can be combined in a manner that allows for the achievement of substantial benefits. Any integration process may require significant time and resources, and we may not be able to manage the process successfully as our ability to acquire and integrate larger or more complex companies, products, or technology in a successful manner is unproven. If we are not able to successfully integrate these acquired businesses with ours or pursue our customer and product strategy successfully, the anticipated benefits of such acquisitions may not be realized fully or may take longer than expected to be realized. Further, it is possible that there could be a loss of our key employees and customers, disruption of ongoing businesses or unexpected issues, higher than expected costs and an overall post-completion process that takes longer than originally anticipated. In addition, the following issues, among others, must be addressed in order to realize the anticipated benefits of our acquisitions, partnerships or investments:

In addition, at times the attention of certain members of our management and resources may be focused on integration of the acquired businesses and diverted from day-to-day business operations, which may disrupt our ongoing business.

We have incurred, and may continue to incur, significant, nonrecurring costs in connection with our acquisitions, partnerships and investments and integrating our operations with those of the acquired businesses, including costs to maintain employee morale and to retain key employees. Management cannot ensure that the elimination of duplicative costs or the realization of other efficiencies will offset the transaction and integration costs in the near term or at all.

We depend upon our IT systems to conduct virtually all of our business operations, ranging from our internal operations and research and development activities to our marketing and sales efforts and communications with our customers and business partners. We have in the past and may in the future be subject to a variety of evolving threats, including but not limited to social-engineering attacks (including through phishing attacks), malicious code (such as viruses and worms), malware (including as a result of advanced persistent threat intrusions), denial-of-service attacks (such as credential stuffing), personnel misconduct or error, ransomware attacks, supply-chain attacks, software bugs, server malfunctions, software or hardware failures, loss or unavailability of data or other information technology assets, adware, telecommunications failures, earthquakes, fires, floods, natural disasters, and other similar threats.

Individuals or entities may attempt to penetrate the security of our platform, or of our network or systems, and to cause harm to our business operations, including by misappropriating our proprietary information or that of our customers, employees and business partners or to cause interruptions of our products and platform. In particular, cyberattacks and other malicious internet-based activity continue to increase in frequency and in magnitude generally, and cloud-based companies have been

Additionally, we depend upon our employees and contractors to appropriately handle confidential and sensitive data, including customer data, and to deploy our IT resources in a safe and secure manner that does not expose our network systems to security breaches or incidents or the loss, alteration, unavailability, or other unauthorized processing of data. We have been and expect to be subject to cybersecurity threats and incidents, including denial-of-service attacks, employee errors or individual attempts to gain unauthorized access to information systems. We also continue to incorporate AI solutions and features into our platform, which may result in security incidents or otherwise increase cybersecurity risks. Further, AI technologies may be used in connection with certain cybersecurity attacks, resulting in heightened risks of security breaches and incidents. Any data security incidents, including internal malfeasance or inadvertent disclosures by our employees or a third party’s fraudulent inducement of our employees to disclose information, unauthorized access or usage, virusthe introduction of viruses or similarother malicious code or any other breach or incident or disruption of our platform, systems, or networks or those of our service providers, such as AWS, could result in loss, corruption, unavailability, or other unauthorized processing of confidential information, and any such event, or the perception that it has occurred, may result in damage to our reputation, erosion of customer trust, loss of customers, litigation, regulatory investigations, fines, penalties and other liabilities. For example, in June and August 2022, we became aware that threat actors had conducted sophisticated social engineering campaigns against some of our employees after having obtained employee names and cell phone numbers from unknown sources. The attack identified in August, which involved smishing text messages that purported to be from our IT department, resulted in the threat actor obtaining some of our employees’ credentials and access to certain data of approximately 209 customers out of our total customer base of approximately 270,000 at that time. We notified and worked with our affected customers. We also notified appropriate regulators and addressed their questions about the incident. We also took steps to remediate the incident, including enhancing our security training, improving our two factor authentication requirements, implementing additional layers of control within our VPN, reducing access to certain internal applications and tools, and increasing the refresh frequency for access to certain internal applications. Industry reports indicate that the threat actors also attacked other technology, telecommunication and cryptocurrency companies.

Furthermore, we are required to comply with laws and regulations that require us to maintain the security of personal information and we may have contractual and other legal obligations to notify customers, regulators, government agencies, impacted individuals or other relevant stakeholders of security breaches. Such disclosures are costly, and the disclosures or the failure to comply with such requirements could lead to adverse consequences. If we (or a third party upon whom we rely) experience a security incident or are perceived to have experienced a security incident, we may experience adverse consequences. These consequences may include: government enforcement actions and other actions or proceedings (for example, investigations, audits, and inspections), and related fines, penalties, required remedial actions, or other obligations and liabilities; additional reporting requirements and/or oversight; restrictions on processing or transferring data (including personal data); claims, demands, and litigation (including class claims); indemnification obligations; monetary fund diversions; interruptions in our operations (including availability of data); financial loss and other similar harms. Actual and perceived security incidents and attendant consequences could also lead to negative publicity and reputational harm, may cause our customers to lose confidence in the effectiveness of our security measures and require us to expend significant capital and other resources to respond to and/or mitigate the security incident. Accordingly, if our cybersecurity measures or those of AWS or our service providers fail to protect against unauthorized access, attacks (which may include sophisticated cyberattacks), or if our employees or contractors compromise or the mishandling ofmishandle data, by our employees and contractors, then our reputation, customer trust, business, results of operations and financial condition could be adversely affected.

While we maintain errors, omissions and cyber liability insurance policies covering certain security and privacy damages, we cannot be certain that our existing insurance coverage will continue to be available on acceptable terms or will be

We and our customers are subject to numerous domestic (for example, the California Consumer Privacy Act of 2018 (“CCPA”)) and foreign (for example, the General Data Protection Regulation (“GDPR”) in the European Union (“EU”)) privacy, data protection and data security laws and regulations that restrict the collection, use, disclosure and processing of personal information, including financial and health data. These laws and regulations are expanding globally, evolving, are being tested in courts, may result in increasing regulatory and public scrutiny of our practices relating to personal information and may increase our exposure to regulatory enforcement action, sanctions and litigation. The breadth and depth of changes in data protection obligations has required significant time and resources, including a review of our technology and systems currently in use against the requirements of GDPR.

The CCPA (as amended by the California Privacy Rights Act of 2020) imposes obligations on businesses to which it applies. These obligations include, but are not limited to, providing specific disclosures in privacy notices and affording California residents (both consumers and employees) certain rights related to their personal information. The CCPA allows for statutory fines for noncompliance. In addition, the California Privacy Rights Act of 2020 (“CPRA”), which became enforceable as of January 1, 2023, expanded the CCPA protections for consumers and employees. Similar laws have been enacted or been proposed at the state and federal levels. For example, Connecticut, Utah, Virginia and Colorado have each passed laws similar to but different from the CCPA that took effect in 2023; Florida, Montana, Oregon and CPRATexas have enacted similar legislation that becomes effective in 2024; Tennessee, Delaware, New Jersey and Iowa have taken orpassed such a law that will take effect in 2023.2025; and Indiana has enacted similar legislation that will become effective in 2026. If we become subject to new privacy, data protection and data security laws, the risk of enforcement action against us could increase because we may become subject to additional obligations, and the number of individuals or entities that can initiate actions against us may increase, including individuals, via a private right of action, and state actors.

Outside the United States, an increasing number of laws, regulations, and industry standards apply to privacy, data protection and data security. For example, the GDPR, the United Kingdom’s Data Protection Act 2018 (“UK GDPR”) and the new Swiss Federal Act on Data Protection, impose strict requirements for processing the personal information of individuals protected by the legislation, whether their data is processed within or outside the European Economic Area (“EEA”), the United Kingdom (“UK”) and Switzerland, respectively (such jurisdictions, collectively, “Europe”). For example, the GDPR imposes significant requirements regarding the processing of individuals’ personal information, including in relation to transparency, lawfulness of processing, individuals’ privacy rights, compliant contracting, data minimization, data breach notification, data re-usage, data retention, security of processing and international data transfers. Under the GDPR and UK GDPR, government regulators may impose temporary or definitive bans on data processing or data transfers, require a company to delete data, as

Further, the interpretation and application of new domestic and foreign laws and regulations in many cases is uncertain, and our legal and regulatory obligations in such jurisdictions are subject to frequent and unexpected changes, including the potential for various regulatory or other governmental bodies to enact new or additional laws or regulations, to issue rulings that invalidate prior laws or regulations, or to increase penalties significantly. For example, the EU’s Digital Services Act, and Digital Markets Act and Data Act recently entered into force, whereas proposed laws in Europe includeforce. Also, the Artificial Intelligence Act andUK Parliament is currently debating the Data Act.Protection and Digital Information (No. 2) Bill which, if enacted, will introduce certain changes to the UK’s data protection laws.

Similarly, with our registration as an interconnected VoIP provider for certain products with the Federal Communications Commission (“FCC”), we also must comply with privacy laws associated with customer proprietary network information (“CPNI”) rules in the United States. If we fail or are perceived to have failed to maintain compliance with these requirements,

In addition to our legal obligations, our contractual obligations relating to privacy, data protection and data security have become increasingly stringent due to changes in laws and regulations and the expansion of our offerings. Certain privacy, data protection and data security laws, such as the GDPR and the CCPA, require our customers to impose specific contractual restrictions on their service providers. In addition, we support customer workloads that involve the processing of protected health information and are required to sign business associate agreements with customers that subject us to requirements under the federal Health Insurance Portability and Accountability Act of 1996, as amended by the Health Information Technology for Economic and Clinical Health Act of 2009, as well as state laws that govern health information.

Our actual or perceived failure to comply with laws, regulations, contractual commitments, or other actual or asserted obligations, including certain industry standards, regarding privacy, data protection and data security could lead to costly legal action, adverse publicity, significant liability, inability to process data, and decreased demand for our services, which could adversely affect our business, results of operations and financial condition.

As a cumulative example of these risks, because our primary data processing facilities are in the United States, we have experienced hesitancy, reluctance, or refusal by European or multinational customers to continue to use our services due to the potential risks posed as a result of the Court of Justice’s July 2020 ruling in the “Schrems II” case, as well as related guidance from regulators.regulators and the recent enforcement action against Meta by the Irish Data Protection Commission. For example, absent appropriate safeguards or other circumstances, the GDPR and laws in Switzerland and the UK generally restrict the transfer of personal information to countries outside of the EEA, Switzerland and the UK such as the United States, thatStates. On July 10, 2023, the European Commission does not consider as providing an adequate level of privacy, data protection and data security. On March 25, 2022,adopted its adequacy decision for the United States and EU announced an “agreement in principle” to replace the EU-U.S. Privacy Shield transfer framework with the Trans-Atlantic Data Privacy Framework. Progress has since been made towardsBased on this decision, personal information can flow from the establishment of this as a valid transfer mechanism with President Biden’s issuance ofEU to U.S. companies participating in the Executive Order Enhancing Safeguards for United States Signals Intelligence ActivityEU-U.S. Data Privacy Framework without having to put in October 2022. Additionally, on December 13, 2022, the European Commission published a draft adequacy decision on the level ofplace additional data protection of personal datasafeguards. We are certified under the EU-U.S. Data Privacy Framework, but this framework has not yet been established.the UK Extension to the EU-U.S. Data Privacy Framework, and the Swiss-U.S. Data Privacy Framework. If we cannot implement and maintain a valid mechanism for cross-border data transfers, we and our customers may face increased exposure to regulatory actions, substantial fines, and injunctions against processing or transferring personal information from Europe or elsewhere. The inability to importtransfer personal information to the United States could significantly and negatively impact our business operations; limit our ability to collaborate with parties that are subject to data privacy and security laws; or require us to increase our personal information processing capabilities in Europe and/or elsewhere at significant expense. We and our customers are at risk of enforcement actions during such time we continue to require data transfers from Europe for the provision of our services. In addition, outside of Europe, other jurisdictions have proposed and enacted laws relating to cross-border data transfer or requiring personal information, or certain subcategories of personal information, to be stored in the jurisdiction of origin. If we are unable to increase our data processing capabilities and storage in Europe and other countries to limit or eliminate the need for data transfers out of Europe and other applicable countries quickly enough, and other valid solutions for personal information transfers to the United States or other countries are not available or are difficult to implement in the interim, we will likely face continuing reluctance from European and multinational customers to use our services and increased exposure to regulatory actions, substantial fines and injunctions against processing or transferring personal information across borders.

Our success depends, in part, on our ability to protect our brand and the proprietary methods and technologies that we develop under patent and other intellectual property laws. We rely on a combination of patents, copyrights, trademarks, service marks, trade secret laws and other intellectual property laws, contractual provisions, and internal processes, procedures, and controls in an effort to establish, maintain, enforce, and protect our intellectual property and proprietary rights. However, the steps we take to protect our intellectual property may be inadequate. While we have been issued patents in the United States and other countries and have additional patent applications pending, we may be unable to obtain patent protection for the technology covered in our patent applications. In addition, any patents issued to us in the future may not provide us with

We also rely, in part, on contractual confidentiality obligations we impose on our business partners, employees, consultants, advisors, customers and others in our efforts to protect our proprietary technology, processes and methods. These obligations may not effectively prevent unauthorized disclosure or use of our confidential information, and it may be possible for unauthorized parties to copy or access our software or other proprietary technology or information, or to develop similar products independently without ourus having an adequate remedy for unauthorized use or disclosure of our confidential information. In addition, others may independently discover our trade secrets and proprietary information, and in these cases, we may not be able to assert any trade secret rights against those parties.

We may be required to spend significant resources to monitor, enforce, maintain, and protect our intellectual property and proprietary rights. Litigation brought to protect and enforce our intellectual property or proprietary rights could be costly, time-consuming and distracting to management, result in a diversion of significant resources, or the narrowing or invalidation of portions of our intellectual property. Our efforts to enforce our intellectual property or proprietary rights may be met with defenses, counterclaims and countersuits attacking the validity and enforceability of such rights. Our failure to meaningfully protect our intellectual property and proprietary rights, could have an adverse effect on our business, results of operations and financial condition.

We have been sued and may, in the future, be sued by third parties for alleged infringement of their intellectual or other proprietary rights, which could adversely affect our business, results of operations and financial condition.

There is considerable patent and other intellectual property development activity in our industry. We may also introduce or acquire new products or technologies, including in areas where we historically have not participated, which could increase our exposure to intellectual property infringement claims brought by third parties. Our future success depends, in part, on not infringing the intellectual property or proprietary rights of others and we may be unaware of such rights that may cover some or all of our technology or intellectual property. We have from time to time been subject to claims that our products or platform and underlying technology are infringing upon third-party intellectual property or proprietary rights. We may be subject to such claims in the future and we may be found to be infringing upon such rights. Any claims or litigation could cause us to incur significant expenses (including settlement payments and costs associated with litigation) and, if successfully asserted against us, could require that we pay substantial damages or ongoing royalty payments, prevent us from offering our products, or require that we comply with other unfavorable terms.

Additionally, our agreements with customers and other third parties typically include indemnification or other provisions under which we agree to indemnify or are otherwise liable to them for losses suffered or incurred by them as a result of claims of intellectual property infringement. Although we typically limit our liability with respect to such obligations through such agreements, we may still incur substantial liability related to our indemnification obligations.

Our products and platform incorporate open source software, and we expect to continue to incorporate open source software in our products and platform in the future. Few of the licenses applicable to open source software have been interpreted by courts, and there is a risk that these licenses could be construed in a manner that could impose unanticipated conditions or restrictions on our ability to commercialize our products and platform. Although we have implemented policies to regulate the use and incorporation of open source software into our products and platform, we cannot be certain that we have not incorporated open source software in our products or platform in a manner that is inconsistent with such policies. If we fail to comply with open source licenses, we may be subject to certain requirements, including requirements that we offer our products that incorporate the open source software for no cost, that we make available the source code for any modifications or

As a provider of communications products, we are subject to existing or potential FCC regulations relating to privacy, telecommunications, consumer protection and other requirements. In addition, the extension of telecommunications regulations to our non-interconnected VoIP services could result in additional federal and state regulatory obligations and taxes. We are also in discussions with certain jurisdictions regarding potential sales and other taxes for prior periods that we may owe. In the event any of these jurisdictions disagree with management’s assumptions and analysis, the assessment of our tax exposure could differ materially from management's current estimates, which may increase our costs of doing business and negatively affect the prices our customers pay for our services. If we do not comply with FCC rules and regulations, we could be subject to FCC enforcement actions, fines, loss of licenses and possibly restrictions on our ability to operate or offer certain of our products. For example, on January 25, 2023, we received a “cease-and-desist” letter from the FCC related to reported fraudulent traffic on our messaging platform. We subsequently removed the identified traffic. In response to written questions from the FCC, we sent a follow-up letter to the agency on February 10, 2023 detailing our fraud mitigation practices and various planned improvements to reduce future risks. There has been no further communication from the agency on this matter. Any enforcement action by the FCC, which may be a public process, would hurt our reputation in the industry, could erode customer trust, possibly impair our ability to sell our VoIP, and other telecommunications products and/or other services to customers and could adversely affect our business, results of operations and financial condition.

Certain of our products are subject to a number of FCC regulations and laws that are administered by the FCC. Among others, we must comply (in whole or in part) with:

In addition, Congress and the FCC are attempting to mitigate the prevalence of robocalls by requiring participation in a technical standard called SHAKEN/STIR,Signature-based Handling of Asserted Information Using toKENs (“SHAKEN”) and Secure Telephone Identity Revisited (“STIR”) (together, “SHAKEN/STIR”), which allows voice carriers to authenticate caller ID, prohibiting malicious spoofing. The FCC also has open proceedings relating to robocalls and robotexts. While we do not currently expect the FCC to require more than the robocall and robotexting measures that we have started to implement, if the FCC were to implement new regulations or requirements that limited the types of customers allowed to use our platform or overly burdensome requirements for our customers, those actions could limit the customers that we are able to serve.

Similarly, in May 2021, the Biden Administration issued an Executive Order requiring federal agencies to implement additional information technology security measures, including, among other things, requiring agencies to adopt multifactor authentication and encryption for data at rest and in transit to the maximum extent consistent with Federal records laws and other applicable laws. The National Institute of Standards and Technology issued a Secure Software Development Framework (SSDF) on September 30, 2021 and Software Supply Chain Security Guidance (incorporating the SSDF), on February 4, 2022, and on March 7, 2022, the Office of Management and Budget directed federal agencies to incorporate both documents into their software lifecycle and acquisitions practices. The Executive Order also may lead to the development of additional secure software development practices and/or criteria for a consumer software labeling program, the criteria which will reflect a baseline level of secure practices, for software that is developed and sold to the U.S. federal government. Software developers will be required to provide visibility into their software and make security data publicly available. Due to this Executive Order, federal agencies may require us to modify our cybersecurity practices and policies, thereby increasing our compliance costs. If we are unable to meet the requirements of the Executive Order, our ability to work with the U.S. government may be impaired and may result in a loss of revenue.

If we do not comply with any current or future rules or regulations that apply to our business, we could be subject to substantial fines and penalties, and we may have to restructure our offerings, exit certain markets or raise the price of our products. In addition, any uncertainty regarding whether particular regulations apply to our business, and how they apply, could increase our costs or limit our ability to grow.

As we continue to expand internationally, we have become subject to telecommunications laws and regulations in the foreign countries where we offer our products. Internationally, we currently offer our products in more than 180 countries and territories.

Our international operations are subject to country-specific governmental regulation and related actions that have increased and will continue to increase our compliance costs or impact our products and platform or prevent us from offering or providing our products in certain countries. Moreover, the regulation of CPaaS companies like us is continuing to evolve internationally and many existing regulations may not fully contemplate the CPaaS business model or how they fit into the communications regulatory framework. As a result, interpretation and enforcement of regulations often involve significant uncertainties. In many countries, including those in the European Union, a number of our products or services are subject to licensing and communications regulatory requirements which increases the level of scrutiny and enforcement by regulators. Future legislative, regulatory or judicial actions impacting CPaaS services could also increase the cost and complexity of compliance and expose us to liability. For example, in some countries, some or all of the services we offer are not considered regulated telecommunications services, while in other countries they are subject to telecommunications regulations, including but not limited to payment into universal service funds, licensing fees, provision of emergency services, provision of information to support emergency services and number portability. Failure to comply with these regulations could result in our Company being issued remedial directions to undertake independent audits and implement effective systems, processes and practices to ensure compliance, significant fines or being prohibited from providing telecommunications services in a jurisdiction.

Moreover, certain of our products may be used by customers located in countries where voice and other forms of Internet Protocol (“IP”) communications may be illegal or require special licensing or in countries on a U.S. embargo list. Even where our products are reportedly illegal or become illegal or where users are located in an embargoed country, users in those countries may be able to continue to use our products in those countries notwithstanding the illegality or embargo. We may be subject to penalties or governmental action if consumers continue to use our products in countries where it is illegal to do so or if we use a local partner to provide services in a country and the local partner does not comply with applicable governmental regulations. Any such penalties or governmental action may be costly and may harm our business and damage our brand and reputation. We may be required to incur additional expenses to meet applicable international regulatory requirements or be

Our future success depends in part on our ability to obtain allocations of geographical, mobile, regional, local and toll-free direct inward dialing numbers or phone numbers as well as short codes and alphanumeric sender IDs (collectively, “Numbering Resources”) in the United States and foreign countries at a reasonable cost and without overly burdensome restrictions. Our ability to obtain allocations of, assign and retain Numbering Resources depends on factors outside of our control, such as applicable regulations, the practices of authorities that administer national numbering plans or of network service providers from whom we can provision Numbering Resources, such as offering these Numbering Resources with conditional minimum volume call level requirements, the cost of these Numbering Resources and the level of overall competitive demand for new Numbering Resources.

In addition, in order to obtain allocations of, assign and retain Numbering Resources in the EU or certain other regions, we are often required to be licensed by local telecommunications regulatory authorities, some of which have been increasingly monitoring and regulating the categories of Numbering Resources that are eligible for provisioning to our customers. We have obtained licenses and are in the process of obtaining licenses in various countries in which we do business, but in some countries, the regulatory regime around provisioning of Numbering Resources is unclear, subject to change over time, and sometimes may conflict from jurisdiction to jurisdiction. Furthermore, these regulations and governments’ approach to their enforcement, as well as our products and services, are still evolving and we may be unable to maintain compliance with applicable regulations, or enforce compliance by our customers, on a timely basis or without significant cost. Also, compliance with these types of regulation may require changes in products or business practices that result in reduced revenue. Due to our or our customers’ assignment and/or use of Numbering Resources in certain countries in a manner that violates applicable rules and regulations, we have been subjected to government inquiries and audits, and may in the future be subject to significant penalties or further governmental action, and in extreme cases, may be precluded from doing business in that particular country. We have also been forced to reclaim Numbering Resources from our customers as a result of certain events of non-compliance. These reclamations result in loss of customers, loss of revenue, reputational harm, erosion of customer trust, and may also result in breach of contract claims, all of which could have an adverse effect on our business, results of operations and financial condition.

Due to their limited availability, there are certain popular area code prefixes that we generally cannot obtain. Our inability to acquire or retain Numbering Resources for our operations may make our voice and messaging products less attractive to potential customers in the affected local geographic areas. In addition, future growth in our customer base, together with growth in the customer bases of other providers of cloud communications, has increased, which increases our dependence on needing sufficiently large quantities of Numbering Resources. It may become increasingly difficult to source larger quantities of Numbering Resources as we scale and we may need to pay higher costs for Numbering Resources, and Numbering Resources may become subject to more stringent regulation or conditions of usage such as the registration and on-going compliance requirements discussed above.

Additionally, in some geographies, we support number portability, which allows our customers to transfer their existing phone numbers to us and thereby retain their existing phone numbers when subscribing to our voice and messaging products. Transferring existing numbers is a manual process that can take up to 15 business days or longer to complete. Any delay that we experience in transferring these numbers typically results from the fact that we depend on network service providers to transfer these numbers, a process that we do not control, and these network service providers may refuse or substantially delay the transfer of these numbers to us. Number portability is considered an important feature by many potential customers, and if we fail to reduce any related delays, then we may experience increased difficulty in acquiring new customers.

The Federal Controlling the Assault of Non-Solicited Pornography and Marketing Act of 2003 (the “CAN-SPAM Act”) establishes certain requirements for commercial email messages and transactional email messages and specifies penalties for the transmission of email messages that are intended to deceive the recipient as to source or content. Among other things, the CAN-SPAM Act, obligates the sender of commercial emails to provide recipients with the ability to “opt-out” of receiving future commercial emails from the sender. In addition, some states have passed laws regulating commercial email practices that are

The actual or perceived improper sending of text messages or voice calls may subject us to potential risks, including liabilities or claims relating to consumer protection laws and regulatory enforcement, including fines. For example, the Telephone Consumer Protection Act of 1991 (“TCPA”) restricts telemarketing and the use of automatic SMS text messages without explicit customer consent. TCPA violations can result in significant financial penalties, as businesses can incur penalties or criminal fines imposed by the FCC or be fined up to $1,500 per violation through private litigation or state attorneys general or other state actor enforcement. Class action suits are the most common method for private enforcement. This has resulted in civil claims against our company and requests for information through third-party subpoenas. The scope and interpretation of the laws that are or may be applicable to the delivery of text messages or voice calls are continuously evolving and developing. If we do not comply with these laws or regulations or if we become liable under these laws or regulations due to the failure of our customers to comply with these laws by obtaining proper consent, we could face direct liability.

Moreover, certain customers may use our platform to transmit unauthorized, offensive or illegal messages, calls, spam, phishing scams, and website links to harmful applications, reproduce and distribute copyrighted material or the trademarks of others without permission, and report inaccurate or fraudulent data or information. These issues also arise with respect to a portion of those users who use our platform on a free trial basis or upon initial use. These actions are in violation of our policies, in particular, our Acceptable Use Policy. For example, on January 24,25, 2023, we received a cease-and-desist letter from the FCC alleging that we were transmitting illegal robocall traffic that originated from an independent software vendor customer and their end user customer. In response, we have suspended the customers’ accounts and are in the process of responding tosent the FCC regardinga follow-up letter on February 10, 2023 detailing our fraud mitigation practices and various planned improvements to reduce future risks. There has been no further communication from the steps we are taking to prevent new or renewing customers from using our network to transmit illegal robocalls.agency on this matter. Failure to respond appropriately to the FCC’s allegations could allow domestic carriers to begin blocking all voice traffic transmitting from our network. However, our efforts to defeat spamming attacks, illegal robocalls and other fraudulent activity will not prevent all such attacks and activity. Such use of our platform could damage our reputation and we could face claims for damages, regulatory enforcement, copyright or trademark infringement, defamation, negligence, or fraud. Furthermore, enacting more stringent controls on our customers’ use of our platform to combat such violations of our Acceptable Use Policy could increase friction for our legitimate customers and decrease their use of our platform.

Our customers’ and other users’ promotion of their products and services through our platform might not comply with federal, state, and foreign laws or of contractual requirements imposed by carriers, such as the CTIA Shortcode Agreement, The Campaign Registry, and associated policies. We rely on contractual representations made to us by our customers that their use

Additionally, our products may be subject to fraudulent usage, including but not limited to revenue share fraud, domestic traffic pumping, subscription fraud, premium text message scams and other fraudulent schemes. Although our customers are required to set passwords or personal identification numbers to protect their accounts, third parties have in the past been, and may in the future be, able to access and use their accounts through fraudulent means. Furthermore, spammers attempt to use our products to send targeted and untargeted spam messages. We cannot be certain that our efforts to defeat spamming attacks will be successful in eliminating all spam messages from being sent using our platform. In addition, a cybersecurity breach of our customers’ systems could result in exposure of their authentication credentials, unauthorized access to their accounts or fraudulent calls on their accounts, any of which could adversely affect our business, results of operations and financial condition.

The future success of our business depends upon the continued use of the Internet as a primary medium for commerce, communications and business applications. Federal, state or foreign government bodies or agencies have in the past adopted, and may in the future adopt, laws or regulations affecting the use of the Internet as a commercial medium. Changes in these laws or regulations could require us to modify our products and platform in order to comply with these changes. In addition, government agencies or private organizations have imposed and may impose additional taxes, fees or other charges for accessing the Internet or commerce conducted via the Internet. These laws or charges could limit the growth of Internet-related commerce or communications generally or result in reductions in the demand for Internet-based products and services such as our products and platform. In particular, a re-adoption

The current legislative and regulatory landscape regarding the regulation of “network neutrality”the Internet is subject to uncertainty. For example, in January 2018, the FCC released an order that repealed the “open Internet rules, in the United States,” often known as “net neutrality,” which President Biden supported during his campaign, could affect the services used by us and our customers. California’s state network neutrality law went into effect on March 10, 2021. A temporary injunction preventing implementation ofIn response to this decision California and a similar law in Vermont expired on April 20, 2022, but a challenge to that law remains pending. A number of other states have adoptedimplemented their own net neutrality rules which mirrored parts of the repealed federal regulations. In October 2023, the FCC voted to begin the process of reinstating substantially all of the net neutrality rules that had been in place prior to the 2018 repeal. We cannot predict the actions the FCC may take, whether any new FCC order or are adoptingstate initiatives regulating providers will be modified, overturned, or consideringvacated by legal action, federal legislation, or executive actionsthe FCC itself, or the degree to which further regulatory action – or inaction – may adversely affect our business. Should the FCC not reinstate net neutrality or if state initiatives codifying similar protections are modified, overturned, or vacated, internet service providers may be able to limit our users’ ability to access our platform or make our platform a less attractive alternative to our competitors’ applications. On the other hand, if limits are imposed on the types of traffic that would regulateU.S. domestic carriers can carry over their broadband networks, it could adversely affect the conductamount of broadband providers. carrier-originated traffic that we carry. In a related regulatory context, while the EU requires equal access to internet content, under its Digital Single Market initiative the EU may impose additional requirements that could increase our costs. If new FCC, EU, or other rules directly or inadvertently impose costs on online providers like our business, our expenses may rise. Were any of these outcomes to occur, our ability to retain existing users or attract new users may be impaired, our costs may increase, and our business may be significantly harmed.

In addition, the use of the Internet as a business tool could be adversely affected due to delays in the development or adoption of new standards and protocols to handle increased demands of Internet activity, security, reliability, cost, ease-of-use, accessibility and quality of service. The performance of the Internet and its acceptance as a business tool has been adversely affected by “viruses,” “worms,” and similar malicious programs. If the use of the Internet is reduced as a result of these or other issues, then demand for our products could decline, which could adversely affect our business, results of operations and financial condition.

Certain of our products and services may be subject to export control and economic sanctions laws and regulations, including the U.S. Export Administration Regulations, U.S. Customs regulations, and various economic and trade sanctions regulations administered by the U.S. Treasury Department’s Office of Foreign Assets Control as well as similar laws and regulations in other countries in which we do business. Exports of our products and the provision of our services must be made in compliance with these requirements. Although weWe take precautions to prevent our products and services from being provided in violation of such laws,laws; however, we are aware of previous exports of certain of our products to a small number of persons and organizations that are the subject of U.S. sanctions or are located in countries or regions subject to U.S. sanctions. If we fail to comply with these laws and regulations, we and certain of our employees could be subject to substantial civil or criminal penalties, including: the possible loss of export privileges; fines, which may be imposed on us and responsible employees or managers; and, in extreme cases, the incarceration of responsible employees or managers. Any change in trade protection laws, policies, export, sanctions and other regulatory requirements affecting trade and investments, shift in the enforcement or scope of existing regulations, or change in the countries, governments, persons or technologies targeted by such regulations, could also result in decreased use of our products and services, or in our decreased ability to export our products or provide our services to existing or prospective customers with international operations. Any decreased use of our products and services or limitations on our ability to export our products and provide our services could adversely affect our business, results of operations and financial condition.

Further, we incorporate encryption technology into certain of our products. Various countries regulate the import of certain encryption technology, including through import permitting and licensing requirements, and have enacted laws that could limit our customers’ ability to import our products into those countries. Encryption products and the underlying technology may also be subject to export control restrictions. Governmental regulation of encryption technology and regulation of exports of encryption products, or our failure to obtain required approval for our products, when applicable, could harm our international sales and adversely affect our revenue. Compliance with applicable regulatory requirements regarding the export of our products and provision of our services, including with respect to new releases of our products and services, may create delays in the introduction of our products and services in international markets, prevent our customers with international

We are also subject to U.S. and foreign anti-corruption and anti-bribery laws, including the FCPA, the UK Bribery Act 2010, and other anti-corruption laws and regulations in the countries in which we conduct activities. Anti-corruption laws are interpreted broadly and generally prohibit companies, their employees, agents, representatives, business partners, and third partiesthird-party intermediaries from directly or indirectly authorizing, offering, or providing, improper payments or things of value to recipients in the public or private sector, and also require that we maintain accurate books and records and adequate internal controls and compliance procedures designed to prevent violations. We sometimes leverage third parties to sell our products and conduct our business abroad. We, our employees, agents, representatives, business partners and third-party intermediaries may have direct or indirect interactions with officials and employees of government agencies or state-owned or affiliated entities and we may be held liable for the corrupt or other illegal activities of these employees, agents, representatives, business partners or third-party intermediaries even if we do not explicitly authorize such activities. We cannot assure youIt is possible that none of our employees, agents, representatives, business partners or third-party intermediaries willcould fail to comply with our policies and applicable laws and regulations, for which we may ultimately be held responsible. Any allegations or violation of the FCPA or other applicable anti-bribery and anti-corruption laws and anti-money laundering laws could result could result in whistleblower complaints, sanctions, settlements, prosecution, enforcement actions, significant fines and penalties, damages, adverse media coverage, investigations, loss of export privileges, severe criminal or civil sanctions, or suspension or debarment from government contracts, all of which may have an adverse effect on our reputation, business, results of operations, and prospects. Responding to any investigation or action willwould likely result in a materially significant diversion of management’s attention and resources, and significant defense costs and other professional fees.

From time to time, private entities and inbox service providers impose requirements that impact our and our customers’ ability to use and deliver email. For example, some of our IP addresses have become, and we expect will continue to be, listed with one or more denylisting entities due to the messaging practices of our customers and other users. We may be at an increased risk of having our IP addresses denylisted due to our scale and volume of email processed, compared to our smaller

Additionally, inbox service providers can block emails from reaching their users or categorize certain emails as “promotional” emails and, as a result, direct them to an alternate or “tabbed” section of the recipient’s inbox. The implementation of new or more restrictive policies by inbox service providers may make it more difficult to deliver our customers’ emails, particularly if we are not given adequate notice of a change in policy or struggle to update our platform or services to comply with the changed policy in a reasonable amount of time. If the open rates of our customers’ emails are negatively impacted by the actions of inbox service providers to block or categorize emails then customers may question the effectiveness of our platform and cancel their accounts. This, in turn, could harm our business, financial condition and results of operations.

We are and may in the future become subject to legal proceedings and claims that arise in the ordinary course of business, such as disputes or employment claims made by our current or former employees. Any litigation, whether meritorious or not, could harm our reputation, will increase our costs and may divert management’s attention, time and resources, which may in turn seriously harm our business. Insurance might not cover such claims or the costs to defend such claims, might not provide sufficient payments to cover all the costs to resolve one or more such claims, and might not continue to be available on terms acceptable to us. A claim brought against us that is uninsured or underinsured could result in unanticipated costs and could seriously harm our business. If we are required to make substantial payments or implement significant changes to our operations as a result of legal proceedings or claims, our business, results of operations and financial condition could be adversely affected.

As our international operations expand, our exposure to the effects of fluctuations in currency exchange rates grows. For example, global geopolitical events, such as the war in Ukraine and conflict in the Middle East, economic events, public health epidemics and pandemics such as the COVID-19 pandemic, trade tariff developments and other events have caused global economic uncertainty and variability in foreign currency exchange rates. While we have primarily transacted with customers and business partners in U.S. dollars, we have also conducted business in currencies other than the U.S. dollar. We expect to significantly expand the number of transactions with customers that are denominated in foreign currencies in the future as we continue to expand our business internationally. We also incur expenses for some of our network service provider costs outside of the United States in local currencies and for employee compensation and other operating expenses at our non-U.S. locations in the respective local currency. Fluctuations in the exchange rates between the U.S. dollar and other currencies could result in an increase to the U.S. dollar equivalent of such expenses.

In addition, our international subsidiaries maintain net assets that are denominated in currencies other than the functional operating currencies of these entities. As we continue to expand our international operations, we become more exposed to the effects of fluctuations in currency exchange rates. Accordingly, changes in the value of foreign currencies relative to the U.S. dollar can affect our results of operations due to transactional and translational remeasurements. As a result of such foreign currency exchange rate fluctuations, it could be more difficult to detect underlying trends in our business and results of operations. In addition, to the extent that fluctuations in currency exchange rates cause our results of operations to differ from our expectations or the expectations of our investors and securities analysts who follow our stock, the trading price of our Class A common stock could be adversely affected.

We recentlyhave implemented a program to hedge transactional exposure against the Euro, and may do so in the future with respect to other foreign currencies. We also use derivative instruments, such as foreign currency forward and option contracts,

As of December 31, 2022,2023, we had $1.0 billion of indebtedness outstanding (excluding intercompany indebtedness). Our indebtedness may:

In addition, the indenture which governs our 3.625% notes due 2029 (the “2029 Notes”) and our 3.875% notes due 2031 (the “2031 Notes,” and together with the 2029 Notes, the “Notes”) contains restrictive covenants that limit our ability to engage in activities that may be in our long-term best interest. Our failure to comply with those covenants could result in an event of default which, if not cured or waived, could permit the trustee, or permit the holders of the Notes to cause the trustee, to declare

If our cash flows and capital resources are insufficient to fund our debt service obligations, we could face substantial liquidity problems and may be forced to reduce or delay investments and capital expenditures, orexpenditures. We may be forced to sell assets, seek additional capital, or restructure or refinance our indebtedness, including the Notes. Our ability to restructure or refinance our debt will depend on, among other things, the condition of the capital markets and our financial condition at such time. Any refinancing of our debt could be at higher interest rates and may require us to comply with more onerous covenants, which could further restrict our business operations. The terms of existing or future debt instruments and the indenture that governs the Notes may restrict us from adopting some of these alternatives. In addition, any failure to make payments of interest and principal on our outstanding indebtedness on a timely basis would likely result in a reduction of our credit rating, which could harm our ability to incur additional indebtedness and our financial condition. In the absence of such cash flows and resources, we could face substantial liquidity problems and might be required to dispose of material assets or operations to meet our debt service and other obligations.

We intend to continue to make investments to support our business and may require additional funds. In particular, we may seek additional funds to develop new products and enhance our platform and existing products, expand our operations, including our sales and marketing organizations and our presence outside of the United States, improve our infrastructure or acquire complementary businesses, technologies, services, products and other assets. In addition, we may use a portion of our cash to satisfy tax withholding and remittance obligations related to outstanding restricted stock units. Accordingly, we may need to engage in equity or debt financings to secure additional funds. If we raise additional funds through future issuances of equity or convertible debt securities, our stockholders could suffer significant dilution, and any new equity securities we issue could have rights, preferences and privileges superior to those of holders of our Class A common stock and Class B common stock. Any debt financing that we may

We rely on assumptions and estimates to calculate certain of our key metrics, such as Active Customer Accounts and Dollar-Based Net Expansion Rate. Our key metrics are not based on any standardized industry methodology and are not necessarily calculated in the same manner or comparable to similarly titled measures presented by other companies. Similarly, our key metrics may differ from estimates published by third parties or from similarly titled metrics of our competitors due to differences in methodology. The numbers that we use to calculate Active Customer Accounts and Dollar-Based Net Expansion Rate are based on internal data. While these numbers are based on what we believe to be reasonable judgments and estimates for the applicable period of measurement, there are inherent challenges in measuring usage. We regularly review and may adjust our processes for calculating our internal metrics to improve their accuracy. If investors or analysts do not perceive our metrics to be accurate representations of our business, or if we discover material inaccuracies in our metrics, our reputation, business, results of operations, and financial condition would be harmed.

The preparation of financial statements in conformity with U.S. GAAPgenerally accepted accounting principles (“GAAP”) requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. We base our estimates on historical experience and on various other assumptions that we believe to be reasonable under the circumstances, as provided in Part I,II, Item 2,7, “Management’s Discussion and Analysis of Financial Condition and Results of Operations.” The results of these estimates form the basis for making judgments about the carrying values of assets, liabilities and equity, and the amount of revenue and expenses that are not readily apparent from other sources. Assumptions and estimates used in preparing our consolidated financial statements include those related to revenue recognition and business combinations. Our results of

A change in accounting standards or practices may have a significant effect on our results of operations and may even affect our reporting of transactions completed before the change is effective. New accounting pronouncements and varying interpretations of accounting pronouncements have occurred and may occur in the future. Changes to existing rules or the questioning of current practices may adversely affect our reported financial results or the way we conduct our business. For example, Accounting Standards Codification (“ASC”) 842, “Leases” that became effective January 1, 2019, had a material impact on our consolidated financial statements as described in detail in Note 2 to the consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2020. Adoption of these types of accounting standards and any difficulties in implementation of changes in accounting principles, including the ability to modify our accounting systems, could cause us to fail to meet our financial reporting obligations, which result in regulatory discipline and harm investors' confidence in us.

We review our intangible assets for impairment when events or changes in circumstances indicate the carrying value may not be recoverable. Goodwill is required to be tested for impairment at least annually. As of December 31, 2022,2023, we carried a net $6.1$5.6 billion of goodwill and intangible assets. An adverse change in market conditions or significant changes in accounting conclusions, particularly if such changes have the effect of changing one of our critical assumptions or estimates, could result in a change to the estimation of fair value that could result in an impairment charge to our goodwill or intangible assets. For example, during the year ended December 31, 2023, we recorded an impairment of intangible assets related to Segment totaling

As a public company, we are required to maintain internal control over financial reporting and to report any material weaknesses in such internal control. Section 404 of the Sarbanes-Oxley Act of 2002 (the “Sarbanes-Oxley Act”) requires that we evaluate and determine the effectiveness of our internal control over financial reporting and provide a management report on internal control over financial reporting. A material weakness is a deficiency, or combination of deficiencies, in internal control over financial reporting, such that there is a reasonable possibility that a material misstatement of our financial statements will not be prevented or detected on a timely basis.

Our current controls and any new controls that we develop may become inadequate because of changes in conditions in our business. Further, weaknesses in our disclosure controls and internal control over financial reporting may be discovered in the future. In addition, if we acquire additional businesses, we may not be able to successfully integrate the acquired operations and technologies and maintain internal control over financial reporting, if applicable, in accordance with the requirements of Section 404 of the Sarbanes-Oxley Act. Any failure to develop or maintain effective controls or any difficulties encountered in their implementation or improvement could harm our results of operations or cause us to fail to meet our reporting obligations and may result in a restatement of our financial statements for prior periods. Any failure to implement and maintain effective internal control over financial reporting also could adversely affect the results of periodic management evaluations and annual independent registered public accounting firm attestation reports regarding the effectiveness of our internal control over financial reporting that we are required to include in our periodic reports that will be filed with the SEC. Ineffective disclosure controls and procedures and internal control over financial reporting could also cause investors to lose confidence in our reported financial and other information, and could have a material and adverse effect on our business, results of operations and

As of December��December 31, 2022,2023 we had U.S. federal, state and foreign net operating loss carryforwards (“NOLs”), of $3.7$3.4 billion, $2.7$2.6 billion and $498.5 million,$1.0 billion, respectively. Utilization of these NOL carryforwards depends on our future taxable income, and there is risk that a portion of our existing NOLs could expire unused, and that even if we achieve profitability, the use of our unexpired NOLs would be subject to limitations, which could materially and adversely affect our operating results. U.S. federal NOLs generated in taxable years beginning before January 1, 2018, may be carried forward only 20 years to offset future taxable income, if any. Under current law, U.S. federal NOLs generated in taxable years beginning after December 31, 2017, can be carried forward indefinitely, but the deductibility of such U.S. federal NOLs in taxable years beginning after December 31, 2020, is limited to 80% of taxable income. It is uncertain if and to what extent various states will conform to federal law.

Under Sections 382 and 383 of the Internal Revenue Code of 1986, as amended (the “Code”), and corresponding provisions of state law, a corporation that undergoes an “ownership change” (generally defined as a greater than 50-percentage-point cumulative change (by value) in the equity ownership of certain stockholders over a rolling three-year period) is subject to limitations on its ability to utilize its pre-change NOLs and other pre-change tax attributes to offset post-change taxable income and taxes. Our existing NOLs and other tax attributes may be subject to limitations arising from previous ownership changes, and if we undergo an ownership change in the future, our ability to utilize NOLs could be further limited by Section 382 of the Code. Future changes in our stock ownership, some of which may be outside of our control, could result in an ownership change under Section 382 of the Code. In addition, at the state level, there may be periods during which the use of NOL carryforwards is suspended or otherwise limited, which could accelerate or permanently increase state taxes owed.

Significant judgments and estimates are required in determining our provision for income taxes and other tax liabilities. Our tax expense may be impacted, for example, if tax laws change or are clarified to our detriment or if tax authorities successfully challenge the tax positions that we take, such as, for example, positions relating to the arms-lengtharm’s-length pricing standards for our intercompany transactions and our indirect tax positions. In determining the adequacy of our provision for

We conduct operations in many tax jurisdictions throughout the United States and internationally. In many of these jurisdictions, non-income-based taxes, such as sales, VAT, GST,value-added tax, goods and services tax, and telecommunications taxes, are assessed on our operations or our sales to customers. We are subject to indirect taxes, and may be subject to certain other taxes, in some of these jurisdictions. We collect certain telecommunications-based taxes from our customers in certain jurisdictions, and we expect to continue expanding the number of jurisdictions in which we will collect these taxes in the future.

Many states are also pursuing legislative expansion of the scope of goods and services that are subject to sales and similar taxes as well as the circumstances in which a vendor of goods and services must collect such taxes. Following the United States Supreme Court decision in South Dakota v. Wayfair, Inc., states are now free to levy taxes on sales of goods and services based on an “economic nexus,” regardless of whether the seller has a physical presence in the state. Any additional fees and taxes levied on our services by any state may adversely impact our results of operations.

Historically, we have not billed or collected taxes in certain jurisdictions and, in accordance with generally accepted accounting principles in the United States (“U.S. GAAP”),GAAP, we have recorded a provision for our tax exposure in these jurisdictions when it is both probable that a liability has been incurred and the amount of the exposure can be reasonably estimated. We reserved $29.1$18.0 million and $20.6$22.2 million for domestic jurisdictions and jurisdictions outside of the United States, respectively, on our December 31, 20222023 balance sheet for these tax payments. These estimates include several key assumptions, including, but not limited to, the taxability of our products, the jurisdictions in which we believe we have nexus or a permanent establishment, and the sourcing of revenues to those jurisdictions. In the event these jurisdictions challenge our assumptions and analysis, our actual exposure could differ materially from our current estimates and reserves. If the actual payments we

We are in discussions with certain jurisdictions regarding potential sales and other indirect taxes for prior periods that we may owe. If any of these jurisdictions disagree with management'smanagement’s assumptions and analysis, the assessment of our tax exposure could differ materially from management'smanagement’s current estimates. For example, in 2020, San Francisco City and County has assessed us for $38.8 million in taxes, including interest and penalties, which exceeded the $11.5 million we had accrued for that assessment. We have paid the full amount as required by law,under protest and the payment made in excess of the accrued amount is reflected as a deposit on our balance sheet. We believe, however, that this assessment is incorrect and, after failing to reach a settlement, filed a lawsuit on May 27, 2021 contesting the assessment. The trial is expectedWe entered into a settlement agreement in November 2023 pursuant to bewhich San Francisco paid us $18.0 million in the summersettlement of 2023. However, litigation is uncertain and a ruling against us may adversely affect our financial position and results of operations.claims.

We generally conduct our global operations through subsidiaries and report our taxable income in various jurisdictions worldwide based upon our business operations in those jurisdictions. In particular, our intercompany relationships are subject to complex transfer pricing regulations administered by taxing authorities in various jurisdictions. Also, our tax expense could be affected depending on the applicability of withholding and other taxes (including withholding and indirect taxes on software licenses and related intercompany transactions) under the tax laws of certain jurisdictions in which we have business operations. The relevant revenue and taxing authorities may disagree with positions we have taken generally, or our determinations as to the value of assets sold or acquired or income and expenses attributable to specific jurisdictions. If such a disagreement were to occur, and our position were not sustained, we could be required to pay additional taxes, interest and penalties, which could result in one-time tax charges, higher effective tax rates, reduced cash flows and lower overall profitability of our operations.

We are subject to income taxes in both the United States and numerous international jurisdictions. Significant judgment is required in determining our worldwide provision for income taxes. In the ordinary course of our business, there are many transactions and calculations where the ultimate tax determination is uncertain. Our effective tax rates may fluctuate significantly on a quarterly basis because of a variety of factors, including changes in the mix of earnings and losses in countries with differing statutory tax rates, changes in our business or structure, changes in tax laws that could adversely impact our income or non-income taxes or the expiration of or disputes about certain tax agreements in a particular country. We are subject to audit by various tax authorities. In accordance with U.S. GAAP, we recognize income tax benefits, net of required valuation allowances and accrual for uncertain tax positions. Although we believe our tax estimates are reasonable, the final

Changes in tax laws (including in response to the COVID-19 pandemic) or tax rulings, or changes in interpretations of existing laws, could cause us to be subject to additional income-based taxes and non-income taxes (such as payroll, sales, use, value-added, digital tax, net worth, property, and goods and services taxes), which in turn could materially affect our financial position and results of operations. Additionally, new, changed, modified, or newly interpreted or applied tax laws could increase our customers’ and our compliance, operating and other costs, as well as the costs of our products. For example, on August 16, 2022, the Inflation Reduction Act of 2022 was signed into law, with tax provisions primarily focused on implementing a 15% minimum tax on global adjusted financial statement income, effective for tax years beginning after December 31, 2022, and a 1% excise tax on share repurchases occurring after December 31, 2022, which may affectresulted in an excise tax payable calculated on our 2023 share repurchase program.repurchases.

As another example, beginning in 2022, the Tax Cuts and Jobs Act of 2017 (the “Tax Act”) eliminates the option to deduct research and development expenditures currently and requires taxpayers to capitalize and amortize them over five or fifteen years pursuant to Section 174 of the Code, which impacts our effective tax rate and our cash tax liability in 2022.2023. If the requirement to capitalize Section 174 expenditures is not modified by legislation, it may alsowill continue to impact our effective tax rate and our cash tax liability in the future.liability.

The trading price of our Class A common stock has, and may continue to, fluctuate significantly in response to numerous factors, many of which are beyond our control and may not be related to our operating performance, including:

In addition, in the past, following periods of volatility in the overall market and the market price of a particular company’s securities, securities class action litigation has often been instituted against these companies. This litigation, if instituted against us, could result in substantial costs and a diversion of our management’s attention and resources.

The market price of our Class A common stock could decline as a result of substantial sales of our Class A common stock, particularly sales by our directors, executive officers and significant stockholders, or the perception in the market that holders of a large number of shares intend to sell their shares. Additionally, the shares of Class A common stock subject to outstanding options and restricted stock unit awards under our equity incentive plans and the shares reserved for future issuance under our equity incentive plans will become eligible for sale in the public market upon issuance, subject to applicable insider trading policies.

In February 2023, we announced that our board of directors authorized the repurchase of up to $1.0 billion of our Class A common stock from time to time through a share repurchase program. Under our share repurchase program, we may make repurchases of stock through a variety of methods, including open share market purchases, privately negotiated purchases, entering into one or more confirmations or other contractual arrangements with a financial institution counterparty to effectuate one or more accelerated stock repurchase contracts, forward purchase contracts or similar derivative instruments, Dutch auction tender offers, or through a combination of any of the foregoing, in accordance with applicable federal securities laws. Our share repurchase program terminates at 11:59 pm Pacific Time on December 31, 2024, does not obligate us to repurchase any specific number of shares, and may be suspended at any time at our discretion and without prior notice. The timing and amount of any repurchases, if any, will be subject to liquidity, stock price, market and economic conditions, compliance with applicable legal requirements such as Delaware surplus and solvency tests and other relevant factors. Any failure to repurchase stock after we have announced our intention to do so may negatively impact our reputation and investor confidence in us and may negatively impact our stock price.

The existence of our share repurchase program could cause our stock price to be higher than it otherwise would be and could potentially reduce the market liquidity for our stock. Although our share repurchase program is intended to enhance long-term stockholder value, there is no assurance that it will do so because the market price of our Class A common stock may decline below the levels at which we repurchase shares, and short-term stock price fluctuations could reduce the effectiveness of the program.

Repurchasing our Class A common stock reduces the amount of cash we have available to fund working capital, capital expenditures, strategic acquisitions or business opportunities, and other general corporate purposes, and we may fail to realize the anticipated long-term stockholder value of any share repurchase program.

The trading market for our Class A common stock is influenced by the research and reports that securities or industry analysts may publish about us, our business, our market or our competitors. If any of the analysts who cover us change their recommendation regarding our Class A common stock adversely, or provide more favorable relative recommendations about our competitors, the trading price of our Class A common stock would likely decline. If any analyst who covers us were to cease coverage of our company or fail to regularly publish reports on us, we could lose visibility in the financial markets, which in turn could cause the trading price of our Class A common stock or trading volume to decline.

Our amended and restated certificate of incorporation, second amended and restated bylaws and Delaware law contain provisions which could have the effect of rendering more difficult, delaying, or preventing an acquisition deemed undesirable by our board of directors. Among other things, our amended and restated certificate of incorporation and second amended and restated bylaws include provisions:

These provisions, alone or together, could delay or prevent hostile takeovers and changes in control or changes in our management.

Any provision of our amended and restated certificate of incorporation, second amended and restated bylaws or Delaware law that has the effect of delaying, preventing or deterring a change in control could limit the opportunity for our stockholders to receive a premium for their shares of our common stock and could also affect the price that some investors are willing to pay for our Class A common stock.

Our second amended and restated bylaws providesprovide that the Court of Chancery of the State of Delaware is the exclusive forum for the following types of actions or proceedings under Delaware statutory or common law:

The Delaware Forum Provision would not apply to suits brought to enforce a duty or liability created by the Exchange Act or any other claim under the Securities Act, for which the United States District Court for the Northern District of California has sole and exclusive jurisdiction (the “Federal Forum Provision”), as we are based in the State of California. In addition, our second amended and restated bylaws provide that any person or entity purchasing or otherwise acquiring any interest in shares of our capital stock is deemed to have notice of and consented to the Delaware Forum Provision and the Federal Forum Provision; provided, however, that stockholders cannot and will not be deemed to have waived our compliance with the U.S. federal securities laws and the rules and regulations thereunder.

The Delaware Forum Provision and the Federal Forum Provision may limit a stockholder’s ability to bring a claim in a judicial forum that it finds favorable for disputes with us or our directors, officers or employees, which may discourage lawsuits against us and our directors, officers and employees. If a court were to find the Delaware Forum Provision and the Federal Forum Provision in our second amended and restated bylaws to be inapplicable or unenforceable in an action, we may incur additional costs associated with resolving the dispute in other jurisdictions, which could seriously harm our business.

We have never paid dividends and we do not anticipate declaring any cash dividends to holders of our common stock in the foreseeable future. Consequently, investors may need to rely on sales of their Class A common stock after price appreciation, which may never occur, as the only way to realize any future gains on their investment. Investors seeking cash dividends should not purchase our Class A common stock.

Our business operations are subject to interruption by natural disasters, flooding, fire, power shortages, public health epidemics or pandemics, such as COVID-19, terrorism, political unrest, cyber-attacks, geopolitical instability, war, the effects of climate change and other events beyond our control. For example, our corporate headquarters are located in the San Francisco Bay Area, a region known for seismic activity. A significant natural disaster, such as an earthquake, fire or flood, occurring at our headquarters, at one of our other facilities or where a business partner is located could adversely affect our business, results of operations and financial condition. Further, if a natural disaster or man-made problem were to affect our service providers, this could adversely affect the ability of our customers to use our products and platform. Natural disasters, public health epidemics or pandemics, such as the COVID-19 pandemic, and geopolitical events, such as the war in Ukraine and conflict in the Middle East, could cause disruptions in our or our customers’ businesses, national economies or the world economy as a whole.

We also rely on our network and third-party infrastructure and enterprise applications and internal technology systems for our engineering, sales and marketing, and operations activities. Although we maintain incident management and disaster

In addition, computer malware, viruses and computer hacking, fraudulent use attempts and phishing attacks have become more prevalent in our industry, have occurred on our platform in the past and may occur on our platform in the future. Though it is difficult to determine what, if any, harm may directly result from any specific interruption or attack, any failure to maintain performance, reliability, security, integrity and availability of our products and technical infrastructure to the satisfaction of our customers may harm our reputation and our ability to retain existing customers and attract new customers. In addition, global climate change could result in certain types of natural disasters occurring more frequently or with more intense effects. Any such events may result in users being subject to service disruptions or outages, and we may not be able to recover our technical infrastructure in a timely manner to maintain or resume operations, which may adversely affect our financial results.

There is an increasing focus from regulators, certain investors, and other stakeholders concerning ESG matters, both in the United States and internationally. We communicate certain ESG-related initiatives, goals, and/or commitments regarding environmental matters, diversity, responsible sourcing and social investments, and other matters in our annual ESGImpact and DEI Report, on our website, in our filings with the SEC, and elsewhere. These initiatives, goals, or commitments could be difficult to achieve and costly to implement. We could fail to achieve, or be perceived to fail to achieve, our ESG-related initiatives, goals, or commitments. In addition, we could be criticized for the timing, scope or nature of these initiatives, goals, or commitments, or for any revisions to them. To the extent that our required and voluntary disclosures about ESG matters increase, we could be criticized for the accuracy, adequacy, or completeness of such disclosures. Our actual or perceived failure to achieve our ESG-related initiatives, goals, or commitments could negatively impact our reputation, result in ESG-focused investors not purchasing and holding our stock, or otherwise materially harm our business.

None.

Refer to Note 16(b)17(b) to our consolidated financial statements included elsewhere in this Annual Report on Form 10-K for a description of our current material legal proceedings.

Not applicable.

We enable businesses of all sizes to reinventrevolutionize how they engage with their customers. We have seencustomers by delivering seamless, trusted and personalized customer expectations evolve over time whereas the customers have been increasingly requiring more personalized and seamless experiences when they interact with a business. We believe that these experiences are achievable if the businesses understand their customers on a deeper level and communicate with them in the manner and over the channels the customers prefer. We believe that it is no longer sufficient to think about customer engagement in separate contexts of marketing, customer support and product.at scale. Our leading customer engagement platform (“CEP”) solves this problem. Ourcomprises communications APIs that enable developers to embed numerous forms of messaging, voice, and email interactions into their customer-facing applications, as well as software products that target specific engagement needs, including our customer data platform, digital engagement platform empowerscenters, marketing campaigns and advanced account security solutions. This combination of flexible APIs and software solutions helps businesses of all sizes and across numerous industries to create the exact solutions they need to engage their customersbenefit from smarter and more streamlined engagement at every step of the customer journey, through real-time, relevant, personalized communications over a customer preferred communications channel and fuel these communications with real-time comprehensive customer data. With our platform, businesses can personalize every transaction with their customers, build lasting loyalty, cutincluding reduced customer acquisition costs, lasting loyalty and increaseincreased customer lifetime value.

We review a number of operational and financial metrics, including Active Customer Accounts and Dollar-Based Net Expansion Rate, to evaluate our business, measure our performance, identify trends affecting our business, formulate business plans and make strategic decisions.

The following table summarizes our year-over-year revenue growth our number of Active Customer Accounts and Dollar-Based Net Expansion Rate for the years ended December 31, 2023, 2022 and 2021, and 2020.the number of Active Customer Accounts as of December 31, 2023, 2022 and 2021.

We define an Active Customer Account at the end of any period as an individual account, as identified by a unique account identifier, for which we have recognized at least $5 of revenue in the last month of the period. A single organization may constitute multiple unique Active Customer Accounts if it has multiple account identifiers, each of which is treated as a separate Active Customer Account. Active Customer Accounts excludes customer accounts from Zipwhip, Inc. (“Zipwhip”). Communications Active Customer Accounts and Segment Active Customer Accounts are calculated using the same methodology, but using only revenue recognized from accounts in the respective segment. When presented in this Annual Report on Form 10-K, (i) the number of Active Customer Accounts is rounded down to the nearest thousand, (ii) the number of Communications Active Customer Accounts is rounded down to the nearest thousand, and (iii) the number of Segment Active Customer Accounts is rounded down to the nearest hundred.

Our Dollar-Based Net Expansion Rate compares the total revenue from all Active Customer Accounts and customer accounts from Zipwhip in a quarter to the same quarter in the prior year. To calculate the Dollar-Based Net Expansion Rate, we first identify the cohort of Active Customer Accounts and customer accounts from Zipwhip that were Active Customer Accounts or customer accounts from Zipwhip in the same quarter of the prior year. The Dollar-Based Net Expansion Rate is the quotient obtained by dividing the revenue generated from that cohort in a quarter, by the revenue generated from that same cohort in the corresponding quarter in the prior year. When we calculate Dollar-Based Net Expansion Rate for periods longer than one quarter, we use the average of the applicable quarterly Dollar-Based Net Expansion Rates for each of the quarters in such period. Revenue from acquisitions does not impact the Dollar-Based Net Expansion Rate calculation until the quarter following the one-year anniversary of the applicable acquisition, unless the acquisition closing date is the first day of a quarter.

We believe that measuring Dollar-Based Net Expansion Rate, on an aggregate basis and at the segment level, provides a more meaningfulan important indication of the performance of our efforts to increase revenue from existing customers. Our ability to drive growth and generate incremental revenue depends, in part, on our ability to maintain and grow our relationships with existing Active Customer Accounts and to increase their use of ourthe platform. An important way in which we have historically tracked performance in this area is by measuring the Dollar-Based Net Expansion Rate for Active Customer Accounts. Our Dollar-Based Net Expansion Rate increases when such Active Customer Accounts increase their usage of a product, extend their usage of a product to new applications or adopt a new product. Our Dollar-Based Net Expansion Rate decreases when such Active Customer Accounts cease or reduce their usage of a product or when we lower usage prices on a product. As our customers grow their businesses and extend the use of our platform, they sometimes create multiple customer accounts with us for operational or other reasons. As such, when we identify a significant customer organization (defined as a single customer organization generating more than 1% of revenue in a quarterly reporting period) that has created a new Active Customer Account, this new Active Customer Account is tied to, and revenue from this new Active Customer Account is included with, the original Active Customer Account for the purposes of calculating this metric.

The majority of our Communications segment revenue is derived from usage‑basedusage-based fees. The usage-based fees are earned from our communications products when customers access our cloud-based platform. Our usage‑based products primarily include offerings, such as Programmable Messaging, Programmable Voice, Twilio Verifyplatform and others.start using the products. Some examples of the usage‑based fees thatour usage-based products are Messaging and Voice. For Messaging products, we primarily charge include fees related to the number of text messages sent or received using our Programmable Messaging,received. For Voice products, we primarily charge fees for minutes of call duration activity forduration. Some examples of the subscription-based Communications products are Email, Marketing Campaigns and Flex. For these products we recognize revenue evenly over the contract term.

Our Segment segment revenue is derived from Segment and Engage products that are subscription-based. For these products we recognize revenue evenly over the contract term. When our Programmable Voice and the number of authentications for Twilio Verify. In the years ended December 31, 2022, 2021 and 2020, we generated 73%, 72% and 76% of our revenue, respectively, from usage‑based fees.

Most of our usage-based customers gain access to our products and solutions either through anour e-commerce self serviceself-service sign-up format, which requires an upfront prepayment via credit card that is drawn down as they use our products; or forproducts. Pricing is generally based on a publicly available, self-serve pricing matrix that generally allows customers to receive tiered discounts as their usage of our products increases. Many of our larger usage-based customers including enterprise customers,enter into contractual arrangements with us for a negotiated contract is established forperiod of at least 12 months that containmonths. These contracts may include negotiated terms and typically include minimum revenue commitments and which may contain more favorable pricing. Customers onof varying durations. Usage-based customers subject to such contracts are typically either invoiced monthly in arrears for products used orused. In the years ended December 31, 2023, 2022 and 2021, we generated 71%, 73% and 72% of our revenue, respectively, from usage-based fees.

Subscription-based fees are earned in accordance with subscription pricing terms. For our subscription-based products, customers generally enter into negotiated contracts, which are typically one to three years in duration. Subscription customers are generally invoiced in advance at the start of the contract term. In the years ended December 31, 2023, 2022 and 2021, we generated 29%, 27% and 28% of our revenue, respectively, from non-usage‑based fees.

Amounts that have been charged via credit card or invoiced are recorded in revenue, deferred revenue or customer deposits, depending on whether the revenue recognition criteria have been met. Our deferred revenue and customer deposits liability balance is not a meaningful indicator of our future revenue at any point in time because the number of contracts with our invoiced customers that contain terms requiring any form of prepayment is not significant.

We define U.S. revenue as revenue from customers with IP addresses or mailing addresses at the time of registration in the United States. We define international revenue as revenue from customers with IP addresses or mailing addresses at the time of registration outside of the United States.

Our arrangements with network service providers require us to pay fees based on the volume of phone calls initiated or text messages sent, as well as the number of telephone numbers acquired by us to service our customers. Our arrangements with our cloud infrastructure providerproviders require us to pay fees based on our server capacity consumption.

The most significant components of operating expenses are personnel costs, which consist of salaries, benefits, sales commissions and bonuses and stock‑based compensation. We also incur other non‑personnel costs related to our general overhead expenses.

We are focusing our research and development investment in the highest impact product areas for our future. We are investing strategically in alignment with our focus on building a trusted, leading customer engagement platform.

We expect that we will incur costs associated with supporting the growth of our business and to meet the increased compliance requirements associated with our international expansion.business. We may also incur higher than usual losses related to deterioration of quality of certain financial assets caused by the macroeconomic conditions.

Our (provision for) benefit from income taxes consists primarily of income taxes, withholding taxes in foreign jurisdictions in which the Company conducts business and tax benefits related to the release of valuation allowance from historically completed acquisitions.

The primary difference between our effective tax rate and the federal statutory rate relates to the full valuation allowance the Company established on the federal, state and certain foreign net operating losses and credits.

We use the following non‑GAAP financial information, collectively, to evaluate our ongoing operations and for internal planning and forecasting purposes. We believe that non‑GAAP financial information, when taken collectively, may be helpful to investors because it provides consistency and comparability with past financial performance, facilitates period‑to‑period comparisons of results of operations and assists in comparisons with other companies, many of which use similar non‑GAAP financial information to supplement their results of operations reported in accordance with generally accepted accounting principles (“GAAP”). Non‑GAAP financial information is presented for supplemental informational purposes only, should not be considered a substitute for financial information presented in accordance with GAAP and may be different from similarly‑titled non‑GAAP measures used by other companies. Whenever we use a non‑GAAP financial measure, a reconciliation is provided to the most closely applicable financial measure stated in accordance with GAAP. The users of our consolidated financial statements are encouraged to review the related GAAP financial measures and the reconciliation of these non‑GAAP financial measures to their most directly comparable GAAP financial measures.

For the periods presented, we define non‑GAAP gross profit and non‑GAAP gross margin as GAAP gross profit and GAAP gross margin, respectively, adjusted to exclude, as applicable, certain expenses as presented in the table below:

For the periods presented, we define non‑GAAP operating expenses (including categories of operating expenses) as GAAP operating expenses (and categories of operating expenses) adjusted to exclude, as applicable, certain expenses as presented in the table below:

The following table sets forth our results of operations for the periods presented. We have included Zipwhip in our results of operations prospectively after its closing date of July 14, 2021; Twilio Segment after its closing date of November 2, 2020; and all other acquisitions from the respective closing dates of each acquisition. The period-to-period comparison of our historical results are not indicative of the results that may be expected in the future.