Amendment: SEC Form SCHEDULE 13D/A filed by T-Mobile US Inc.

This Item 3 is hereby amended and supplemented as follows: The information set forth in Item 6 of this Schedule 13D is hereby incorporated by reference.

This Item 4 is hereby amended and supplemented as follows: The information set forth in Item 6 of this Schedule 13D is hereby incorporated by reference.

This Item 5 is hereby amended and supplemented as follows: The information contained in the cover pages of this Schedule 13D and the information set forth in Item 6 of this Schedule 13D is incorporated herein by reference. As of the date hereof, the Reporting Persons beneficially own, in aggregate, 592,065,875 shares of Common Stock consisting of (i) 582,065,875 shares of Common Stock held by DT Holding and (ii) 10,000,000 shares of Common Stock held by Signal Bright and subject to the Proxy (of which 10,000,000 of such shares of Common Stock are subject to call options granted by Signal Bright to Deutsche Telekom), representing 53.7% of the shares of the Common Stock outstanding as of February 6, 2026, as reported by the Issuer in its Annual Report on Form 10-K filed with the Commission on February 11, 2026. The number of shares of Common Stock held by Project 6, Project 9 and Signal Bright is based solely on the information provided by SoftBank.

Same as (a) above.

Except as previously reported on this Schedule 13D or in Item 6 below, to the best knowledge of the Reporting Persons, none of the Reporting Persons has effected any transaction in Common Stock in the 60 days preceding the date hereof.

This Item 6 is hereby amended and supplemented as follows: Novation of the SB-DT 2029 Call Option Agreement On March 19, 2026, Project 9, as transferor, Signal Bright, as transferee, and Deutsche Telekom, as continuing party, entered into a Novation Agreement (the "Novation Agreement") relating to the SB-DT 2029 Call Option (as disclosed in Amendment No. 34 to the Schedule 13D filed with the Commission on October 2, 2025). Pursuant to the Novation Agreement, concurrently with the contribution of 10,000,000 shares of Common Stock by Project 9 to Signal Bright (the "Contribution"), Project 9 novated, transferred and assigned all of its rights, liabilities and obligations under the SB-DT 2029 Call Option to Signal Bright, and Signal Bright accepted all such rights, liabilities and obligations and agreed to observe, perform, discharge and be bound by the terms and conditions of the SB-DT 2029 Call Option from and after the Contribution in every way as if Signal Bright were a party thereto in place of Project 9. Intercreditor Agreements and Deutsche Telekom's Right of First Refusal On March 19, 2026, Signal Bright entered into a master confirmation in respect of a variable prepaid forward sale contract (the "Forward Contract") with an unaffiliated dealer (the "Dealer") covering up to 10,000,000 shares of Common Stock. Signal Bright pledged shares of Common Stock (the "Pledged VPF Shares") to secure its obligations under the Forward Contract. Deutsche Telekom will (i) continue to have the right to direct the vote of the Pledged VPF Shares under the Proxy and (ii) such Pledged VPF Shares will continue to be subject to the SB-DT 2029 Call Option. On March 19, 2026, Signal Bright, Deutsche Telekom, and the Dealer entered into an Intercreditor Agreement (the "VPF Intercreditor Agreement") setting forth certain agreements between the parties thereto with respect to the Pledged VPF Shares. Among other things, the VPF Intercreditor Agreement sets forth the conditions under which Deutsche Telekom may exercise its rights to purchase shares of Common Stock under the SB-DT 2029 Call Option and, in the event of certain events of default or termination events occurring under the Forward Contract, grants Deutsche Telekom a right of first refusal (the "DT VPF ROFR") with respect to the Pledged VPF Shares to purchase a number of Pledged VPF Shares equal to the quotient of (i) the early termination amount determined pursuant to a formula provided by the Dealer divided by (ii) the average of the volume-weighted average price of the Common Stock as reported on Bloomberg L.P. page over an applicable number of trading days in an unwind period (the "Average VWAP"), at a purchase price per share equal to the Average VWAP.