Additional Proxy Soliciting Materials (Form DEFA14A)

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of the

Securities Exchange Act of 1934

(Amendment No. )

Filed by the Registrant ☒        Filed by a Party other than the Registrant ☐

Check the appropriate box:

SUNCOKE ENERGY, INC.

(Name of Registrant as Specified In Its Charter)

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

Payment of Filing Fee (Check the appropriate box):

C 1234567890 ENDORSEMENT LINE SACKPACK MR A SAMPLE DESIGNATION (IF ANY) ADD 1 000001 ADD 2 ADD 3 ADD 4 ADD 5 ADD 6 Online Go to www.envisionreports.com/sxc or scan the QR code - login details are located in the shaded bar below. Stockholder Meeting Notice 1234 5678 9012 345 Important Notice Regarding the Availability of Proxy Materials for the SunCoke Energy, Inc. Stockholder Meeting to be Held Virtually on May 14, 2026 at 8:00 a.m. Central Time 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 location of the annual 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 SunCoke Energy, Inc. 2025 Annual Report on SEC Form 10-K and 2026 Annual Meeting Proxy Statement are available at: www.envisionreports.com/sxc Easy Online Access - View your proxy materials and vote. Step 1: Go to www.envisionreports.com/sxc. Step 2: Click on Cast Your Vote or Request Materials. Step 3: Follow the instructions on the screen to log in. Step 4: Make your selections as instructed on each screen for your delivery preferences. Step 5: Vote your shares. When you go online, you can also help the environment by consenting to receive electronic delivery of future materials. 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 April 30, 2026 to facilitate timely delivery. 2 NOT COY 049BRC

Stockholder Meeting Notice The 2026 Annual Meeting of Stockholders of SunCoke Energy, Inc. will be held on May 14, 2026 at 8:00 a.m. Central Time, virtually via the internet at meetnow.global/M4PPXM5. 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 recommend a vote FOR all the nominees listed and FOR Proposals 2 and 3: 1. To elect two directors to the class of directors whose term expires in 2029. 01 - Martha Z. Carnes 02 - Katherine T. Gates 2. To hold a non-binding advisory vote to approve the compensation of the Company's named executive officers ("Say-on-Pay"). 3. To ratify the appointment of KPMG LLP as the Company's independent registered public accounting firm for the fiscal year ending December 31, 2026. In the discretion of the proxies on such other business as may properly come before 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. If you wish to attend and vote at the meeting, please bring this notice with you. 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/sxc. Click Cast Your Vote or Request Materials. - Phone - Call us free of charge at 1-866-641-4276. - Email - Send an email to [email protected] with "Proxy Materials SunCoke Energy, Inc." 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 April 30, 2026.