Exhibit 99.3

Glattpark (Opfikon), 2 April 2025 Notice Tuesday, of 13 Annual May 2025 General Meeting to of the Sunrise holders Communications of American Depositary AG („Sunrise Shares “) („ADSs”) been JPMorgan notified Chase that Bank, the Annual N.A., the General ADS depositary Meeting (the (the „AGM „Depositary “) of Sunrise “ or „will JPMorgan be held”), in has Glatt -park the Depositary (Opfikon), vote Switzerland, the Sunrise on Tuesday, Shares (as 13 defined May 2025, below) at 10:00 underlying am CEST your . If ADSs you wish on the to have agenda in time. items listed below, please direct the Depositary by executing the proxy materials

1. Agenda of the Annual General Meeting The pensation full agenda report, incl the . proposals annual financial of the Board statements of Directors for the financial and the Annual year 2024¹, Report, the including consolidated the com financial -statements reporting for for the the calendar calendar year year 2024, 2024, are the available associated on reports of the auditors, as well as the non-financial www.sunrise.ch/en/corporate/investor-relations/events-presentations. Please find an overview of the agenda items here: 1. Approval of the Consolidated Financial Statements and the Annual Financial Statements for 2024, Vote on the Non-Financial Reporting 2024 and Advisory Vote on the Compensation Report 2024 1.1 Approval of the Consolidated Financial Statements and the Annual Financial Statements for 2024 1.2 Vote on the Non-Financial Reporting 2024 1.3 Advisory Vote on the Compensation Report 2024 2. Appropriation of Financial Result and Dividend 3. Discharge of the Board of Directors and the Persons Entrusted with Management 4. Re-elections to the Board of Directors 4.1 Re-election of the Chairman 4.2 Re-election of Directors 5. Re-elections to the Compensation Committee 6. Re-election of the Auditors 7. Re-election of the Independent Voting Rights Representative 8. Compensation of the Board of Directors and the Executive Committee 8.1 Approval of the Maximum Aggregate Amount of Compensation of the Board of Directors 8.2 Approval of the Maximum Aggregate Amount of the Executive Committee for Financial Year 2026 ¹The (standalone) annual financial statements for the financial year 2024 of Sunrise cover the period from its inception on 3 May 2024 to 31 December 2024. 2 Notice of Annual General Meeting to ADS Holders

2. ADS Voting for Registered Holders As instruct an ADS JPMorgan, holder, you in its are capacity not a shareholder as Depositary, of Sunrise to exercise . However, the voting as an rights ADS attaching holder, you to are the entitled deposited to Sunrise were a holder Class A of Shares ADSs personally and/or Class registered B Shares with (the JPMorgan „Sunrise Shares (an „ADS “) represented Holder”) at by 4:00 your pm ADSs (Eastern if you Daylight Time) on 17 March 2025 (the „Record Date”). If Owner you hold “), you your should Sunrise contact ADSs the through institution a brokerage managing firm, your bank account or nominee for further (a „Beneficial details regarding the AGM and the exercise of voting rights. ded JPMorgan in the proxy reminds materials all eligible received ADS .Holders, Eligible that ADS the Holders deadline have for the submitting choice of voting providing instructions specific voting is inclu-instructions who have not for submitted each agenda valid item and or timely doing instructions nothing. JPMorgan in accordance will not with vote the at proxy the AGM materials for ADS . JPMorgan Holders will not exercise any voting discretion in respect of any deposited Sunrise Shares. All ADS ADS Holders Holders domiciled may submit in the their U.S .voting A. (a „U instructions .S. Holder”) to may the also Depositary submit via their telephone voting instructions or the Internet by . mail returning . If a Voting the voting Instruction instruction Card card is submitted, included but in the no proxy specific materials voting instructions (the „Voting are Instruction provided Card for one “) by or more Directors agenda for announced items or proposals, proposals you as instruct well as for JPMorgan unannounced to vote proposals in favor of and the new proposals agenda of items the Board . of By the giving Voting JPMorgan Instruction voting Card, instructions as applicable, through you are: the Internet, by telephone, or by signing and returning • Certifying that you were an ADS Holder on the Record Date; and • Instructing JPMorgan to vote the Sunrise Shares underlying your ADSs in the manner indicated. 3. Frequently Asked Questions 3.1 Which ADS Holders are entitled to direct JPMorgan to vote? ADS as the Holders Depositary, as of to the vote Record . Date will receive the proxy materials and are entitled to direct JPMorgan, 3.2 Can I attend the AGM in person? through ADS Holders the Internet may not or attend on the the telephone AGM in person or, for U . ADS .S. Holders, Holders by may mailing give voting the Voting instructions Instruction to JPMorgan Card. 3.3 What happens if I do nothing and do not provide any voting instructions? If the you deposited do not provide Sunrise any Shares voting . Such instructions, Sunrise Shares JPMorgan will be will deemed not exercise not to any be voting represented rights in at respect the AGM of . 3.4 When is my voting entitlement fixed? Time) To instruct on 17 the March Depositary 2025 (Record to vote, Date) you must . Your have voting been entitlement an ADS Holder depends at 4:00 on the pm number (Eastern of Daylight ADSs you held at that time. 3 Notice of Annual General Meeting to ADS Holders

3.5 Until when do I have to submit my ADS vote? Your Internet vote by will the be deadline counted as if noted you have in the properly proxy materials submitted . If your you voting are a U instructions .S. Holder your by telephone vote will also or the be counted line as noted if you in have your mailed proxy materials your signed . JPMorgan Voting Instruction will exercise Card the so voting that it rights is received of the registered before the Sunrise dead-Shares underlying your ADSs in the manner you have instructed. 3.6 Am I restricted in trading if I register my ADS? your The registration ADSs. No trading of ADSs restriction with JPMorgan on ADSs (in is case imposed of registered by JPMorgan ADSs) or does Sunrise not affect . ADS the Holders transferability may, the- of refore, Record purchase Date serves or sell only their to determine ADSs at any the time, right including to direct JPMorgan prior to the to AGM vote or at after the AGM the Record of Sunrise Date . . The 3 .7 Can shareholders I vote on at unannounced the AGM? proposals and new agenda items proposed by Agenda during the Item AGM 9 enables as follows: you to vote on unannounced proposals and/or new agenda items put forth Select oppose the any FOR alternative option to or vote new in proposal favor of. the Select Board ABSTAIN of Directors‘ to abstain recommendations from voting. Please . Choose note AGAINST that a share to represented at the AGM that is voted ABSTAIN has the same effect as a vote against the proposal. To instruct the extent JPMorgan a U.S .to Holder vote in does favor not of mark the proposals boxes for of instruction the Board on of their Directors Voting . Instruction Card, they 3 .8 I I change already my voted vote? as an ADS Holder but have changed my mind – how can All (Eastern ADS Holders Daylight may Time) submit on 6 new May voting 2025. The instructions voting instructions via telephone via telephone or the Internet or the before Internet 11:59 last p recei .m. -ved followed by the . Depositary by 11:59 p.m. (Eastern Daylight Time) on 6 May 2025 will be the ones that are U .S. Holders can also submit a new Voting Instruction Card at any time so that it is received before 09:00 a by .m 09:00 . (Eastern a.m .Daylight (Eastern Time) Daylight on Time) 7 May on 2025 7 May . The 2025 Voting will Instruction be the one Card that last is followed received . by the Depositary 3.9 I hold my ADSs through a brokerage firm, bank or nominee – can I still vote? If proxy you are materials a Beneficial will be Owner, distributed i.e., you to such hold entity your .ADSs The institution through a managing brokerage your firm, account bank, or is nominee, regarded the as tions the ADS are Holder returned . Please to them contact by their this specified institution deadline to submit . your voting instructions and ensure your instruc- 3.10 Who should I contact if I have queries? If how you you are can an ADS deliver Holder voting and instructions, you have queries please contact about the JP ADS Morgan voting Chase process, Bank, the N. A AGM . – ADS of Sunrise Shareholder or Services net: www by .shareowneronline telephone: +1 (800) .com/informational/contact 990 1135 (Toll Free) / outside -us/ the U.S. +1 651 53 2128 or via the Inter-If you are a Beneficial Owner, you should contact the institution managing your account for further details regarding the AGM. 4 Notice of Annual General Meeting to ADS Holders