Southern Copper (SCCO) DEFA14AAdditional proxy soliciting materials

Step 1: Go to www.envisionreports.com/SCCO. Step 2: Click on Cast Your Vote or Request Materials. Step 3: Follow the instructions on the screen to log in. www.envisionreports.com/SCCO Online Go to www.envisionreports.com/SCCO or scan the QR code — login details are located in the shaded bar below. Stockholder Meeting Notice 03L56B + + Important Notice Regarding the Availability of Proxy Materials for the Southern Copper Corporation Stockholder Meeting to be Held on May 27, 2022 Under Securities and Exchange Commission rules, you are receiving this notice that the proxy materials for the annual stockholders’ meeting are available on the Internet. Follow the instructions below to view the materials and vote online or request a copy. The items to be voted on and the information on the virtual meeting are on the reverse side. Your vote is important! This communication presents only an overview of the more complete proxy materials that are available to you on the Internet. We encourage you to access and review all of the important information contained in the proxy materials before voting. The proxy statement, proxy card and annual report on Form 10-K are available at: Obtaining a Copy of the Proxy Materials – If you want to receive a copy of the proxy materials, you must request one. There is no charge to you for requesting a copy. Please make your request as instructed on the reverse side on or before May 16, 2022 to facilitate timely delivery. 2NOT Easy Online Access — View your proxy materials and vote. When you go online, you can also help the environment by consenting to receive electronic delivery of future materials. Step 4: Make your selections as instructed on each screen for your delivery preferences. Step 5: Vote your shares. MMMMMMMMMMMM MMMMMMMMM MR A SAMPLE DESIGNATION (IF ANY) ADD 1 ADD 2 ADD 3 ADD 4 ADD 5 ADD 6 ENDORSEMENT_LINE______________ SACKPACK_____________ 1234 5678 9012 345 C 1234567890 COY 000004 MMMMMMM

Here’s how to order a copy of the proxy materials and select delivery preferences: Current and future delivery requests can be submitted using the options below. If you request an email copy, you will receive an email with a link to the current meeting materials. PLEASE NOTE: You must use the number in the shaded bar on the reverse side when requesting a copy of the proxy materials. — Internet – Go to www.envisionreports.com/SCCO. Click Cast Your Vote or Request Materials. — Phone – Call us free of charge at 1-866-641-4276. — Email – Send an email to investorvote@computershare.com with “Proxy Materials Southern Copper Corporation” in the subject line. Include your full name and address, plus the number located in the shaded bar on the reverse side, and state that you want a paper copy of the meeting materials. To facilitate timely delivery, all requests for a paper copy of proxy materials must be received by May 16, 2022. Southern Copper Corporation’s Annual Meeting of Stockholders will be held on May 27, 2022 at 9:00 A.M. Mexico City time, virtually via the internet at meetnow.global/MX79W5S. To access the virtual meeting, you must have the information that is printed in the shaded bar located on the reverse side of this form. Proposals to be voted on at the meeting are listed below along with the Board of Directors’ recommendations. The Board of Directors of Southern Copper Corporation recommends a vote “For” proposals 1, 2, 3 and 4: 1. Election of Directors: 01 – German Larrea Mota-Velasco 02 – Oscar Gonzalez Rocha 03 – Vicente Ariztegui Andreve 04 – Leonardo Contreras Lerdo de Tejada 05 – Enrique Castillo Sanchez Mejorada 06 – Xavier Garcia de Quevedo Topete 07 – Luis Miguel Palomino Bonilla 08 – Gilberto Perezalonso Cifuentes 09 – Carlos Ruiz Sacristan 2. To approve an amendment to the Company’s Directors’ Stock Award Plan to extend the term of the plan for five years. 3. Ratify the Audit Committee’s selection of Galaz,Yamazaki, Ruiz Urquiza S.C., a member firm of Deloitte Touche Tohmatsu Limited, as our independent accountants for 2022. 4. Approve by, non-binding vote, executive compensation. The Board of Directors recommends a vote AGAINST Proposal 5: 5. To vote on a shareholder proposal, if properly presented at the annual meeting. Note: Stockholders will also transact such other business as may properly come before the meeting and at any adjournment or postponements of the meeting. PLEASE NOTE – YOU CANNOT VOTE BY RETURNING THIS NOTICE. To vote your shares you must go online or request a paper copy of the proxy materials to receive a proxy card. Stockholder Meeting Notice