GRI Index Continued Disclosure# Disclosure Topic 2021 Response 102-10 Significant changes to the organization and its supply chain T-Mobile 2021 Form 10-K Part I page 5; Part II pages 28-31 102-11 Precautionary principle or approach T-Mobile 2021 Form 10-K Part III page 115 2021 Corporate Responsibility Report: Our Governance > Corporate Governance Our standard management practices considers many factors, including potential positive and negative societal impacts, when making strategic business decisions. 102-12 External initiatives CEO Action for Diversity & Inclusion Pledge; Founding Signatory Disability:IN’s CEO Letter; Supporter of the Equality Act; Signed the Human Rights Campaign’s letter against discriminatory state legislation targeting the LGBTQ+ community 102-13 Membership of associations CTIA, Global e-Sustainability Initiative (GeSI), BSR, EPA Green Power partnership, RE100 Strategy 102-14 Statement from senior decision-maker 2021 Corporate Responsibility Report: Our Company > CEO Statement 102-15 Key impacts, risks, and opportunities 2021 Corporate Responsibility Report: Our Company > CEO Statement 2021 Corporate Responsibility Report: Our Company > ESG Approach Ethics and Integrity 102-16 Values, principles, standards, and norms of behavior 2021 Corporate Responsibility Report: Our Company > Corporate Vision, Mission, and Values Code of Business Conduct Supplier Code of Conduct 102-17 Mechanisms for advice and concerns about ethics 2021 Corporate Responsibility Report: Our Governance > Ethical Business Practices T-Mobile Speak Up Policy T-Mobile Integrity Line (external reporting site) Governance 102-18 Governance structure 2021 Corporate Responsibility Report: Our Governance > Corporate Governance 2021 Corporate Responsibility Report: Our Company > ESG Approach > ESG Oversight 2022 Proxy Statement 2021 CORPORATE RESPONSIBILITY REPORT OUR PEOPLE OUR GOVERNANCE OUR COMMUNITIES THE ENVIRONMENT THE NUMBERS AND SMALL PRINT 72 OUR COMPANY