²⁶  We measured our 2019-2023 carbon footprint in partnership with Watershed. Watershed methodology follows guidelines from the GHG Protocol Corporate Accounting and Reporting Standard and the Corporate Value Chain (Scope 3) Accounting and Reporting Standard, inclusive of scope 1, 2, and all relevant scope 3 categories. Watershed’s methodology received third-party verification and uses the most recent and relevant emissions guidance. Watershed is a CDP gold accredited global software solutions provider. We received external auditing from Apex, who verified our 2022 and 2023 scope 1 and 2 emissions. Apex is a silver verification solutions provider accredited with CDP, and all of Apex’s lead auditors are either ISO 50001 or ISO 14001 Lead Auditor certified. Starting in the 2022 footprint, we incorporated region-specific power usage effectiveness values from one of our cloud computing partners into the cloud electricity emissions calculation, and we also collected access swipe data across key offices to estimate the percentage of employees commuting into the office. We now separately disclose optional scope 3.6 emissions from business travel accommodations and optional scope 3.7 emissions from energy usage from employees working from home. We still share these categories for transparency, but they are not included in our science-based target per SBTi requirements. Scope 3.6 emissions from business travel include radiative forcing for flights. Optional scope 3.7 emissions from employees working from home are calculated using location-specific carbon intensity factors to account for differences in emission intensity of the energy sources where our employees are working from home. We acquired multiple companies between 2019 and 2022. GHG protocol requires that the emissions from each acquired company are included within our footprint prior to the acquisition close date as well as moving forward. Watershed estimated historical emissions for each acquisition using a proprietary machine learning algorithm, and the estimated historical emissions from applicable acquisitions are included in addition to our actual emissions for the applicable years. After the acquisition close date, these companies are folded into our systems, and their emissions appear in our carbon footprint using actual data. We have restated our 2019-2021 carbon footprints to better account for well-to-tank emissions in scopes 3.3, 3.6, and 3.8 as well as flight fare class for scope 3.6. Our 2023 market-based scope 2 emissions include Renewable Energy Certificates (RECs). Our scope 3.6 business travel emissions increased between 2022 and 2023 in part due to increased UK Department for Environment, Food & Rural Affairs (DEFRA) emission factors for 2023 that were primarily higher because of reduced flight load factors as a consequence of the COVID-19 pandemic.

²⁷ These Renewable Energy Certificates (RECs) only apply to the US-based grid mix for scopes 3.3 and 3.8. The RECs applied to 2021-2022 were purchased with a late 2022 vintage. We distributed the accounting for the RECs within the recommended 21-month window timeframe per Green-E guidance best practices.

²⁸ Energy consumption is defined as electricity usage and all other energy types. We have restated our 2019-2022 energy consumption to be more comprehensive and include other types.

²⁹ Estimated water use is calculated for offices based on internal records and utility bills where available. For offices where water consumption data is unavailable, we estimate water use by applying an average water use (m3) per square foot based on available 2022 data since it is most representative of other offices. These estimates are for freshwater use only and are calculated based on the square footage of all offices we leased during the year.

³⁰ The percentage is calculated based on the square footage of our San Francisco Spear Street office, which is LEED Gold certified, relative to the total square footage of all offices we leased during the year. We do not own any real property.

³¹ In the US, we follow US Equal Employment Opportunity Commission (EEOC) guidelines in how we track employee data. In all other countries where we operate, we follow region-specific data privacy guidelines in how we track employee data. All employee data is pulled from Twilio’s Workday system as of December 31, 2023. This data includes regular and fixed-term employees only. This data includes employees that are fully integrated with Twilio and will exclude non-integrated employees until the year that they are integrated. Mexico is designated as part of Latin America.

³² This result is based on employee ratings for the statement “I would recommend Twilio as a great place to work” as of Q4 2022 for 2022 and as of Q3 2023 for 2023. We conduct an annual employee engagement survey, share the results, and refocus our work based on employee feedback.