Disclosure# Disclosure Topic 2021 Response 305-1 Direct (scope 1) GHG emissions Gross direct (scope 1) GHG emissions in metric tons of CO 2 equivalent: 70,350 MT CO 2 e Gases included in the calculation: CO 2 , CH 4 , N 2 O , HFCs Biogenic CO 2 emissions in metric tons of CO 2 equivalent: 0 MT CO 2 e Base year for the calculation: 2016 ■ The rationale for choosing it: 2016 was the first year of available data for all direct emissions sources across the T-Mobile and Sprint portfolios ■ Emissions in the base year: 61,266 MT CO 2 e ■ The context for any significant changes in emissions that triggered recalculations of base year emissions: The 2016 emissions figures for T-Mobile and Sprint were combined to ensure consistency when comparing base year emissions to current and future reporting periods Source of the emission factors and the global warming potential (GWP) rates used, or a reference to the GWP source: Publicly available emission factors and global warming potential values from the U.S. Environmental Protection Agency (EPA) and the International Panel on Climate Change (IPCC) are used to convert from the native unit of measure (gallons, mmBTU, or MWh) to MT CO 2 e . Emission factors: ■ U.S. EPA Center for Corporate Climate Leadership: “Emission Factors for Greenhouse Gas Inventories”, (2020) 100-year global warming potential values: ■ IPCC: “Fifth Assessment Report (AR5)”, (2014) Consolidation approach for emissions: Operational control Standards, methodologies, assumptions, and/or calculation tools used: scope 1 emissions data is collected, calculated, and reported in accordance with the GHG Protocol and T-Mobile’s standard procedures and guidelines for sustainability reporting. All scope 1 emissions data is verified annually by an independent third party. All scope 1 emissions from sources designated to be within T-Mobile’s operational control are included. All data is historical in nature and based on primary data. For more information, refer to our most recent CDP Climate Change response on our reporting page . GRI Index Continued 2021 CORPORATE RESPONSIBILITY REPORT OUR PEOPLE OUR GOVERNANCE OUR COMMUNITIES THE ENVIRONMENT THE NUMBERS AND SMALL PRINT 78 OUR COMPANY