Early Results of its Tender Offer for 2025 Notes

NOT FOR DISTRIBUTION IN ANY OTHER JURISDICTION WHERE IT IS UNLAWFUL TO DISTRIBUTE THIS DOCUMENT.

THIS ANNOUNCEMENT IS FOR INFORMATION ONLY AND IS NOT AN OFFER TO PURCHASE OR A SOLICITATION OF AN OFFER TO SELL ANY NOTES.

Tullow Oil plc

Early Results of its Tender Offer for 2025 Notes

November 30, 2023 - Tullow Oil plc (the "Company") announces the early results of its previously announced invitation to holders of its outstanding 7.00% Senior Notes due 2025 (the "Notes") to tender such Notes for purchase by the Company for cash (the "Tender Offer") up to an aggregate tender consideration, excluding any accrued and unpaid interest, of U.S.$300,000,000 (the "Aggregate Tender Consideration") in respect of tenders from registered holders of Notes ("Holders") who validly tendered their Notes on or prior to 5:00 p.m., New York City time, on November 29, 2023 (the "Early Tender Deadline").

As of the Early Tender Deadline, U.S.$130,086,000 principal amount of Notes were validly tendered. The table below identifies the principal amount of Notes validly tendered and accepted as of the Early Tender Deadline:

Notes:

• The clearing price per U.S.$1,000 principal amount of Notes validly tendered prior to the Early Tender Deadline and accepted for purchase (the "Clearing Price" or "Early Tender Offer Consideration", as applicable) (exclusive of any accrued and unpaid interest on such Notes from, and including, the last interest payment date applicable to such Notes, which will be paid in addition to the applicable Consideration to, but not including, the Final Payment Date (as defined herein)).

Capitalized terms used in this announcement but not defined herein have the meanings given to them in the offer to purchase dated November 15, 2023 (the "Offer to Purchase").

The Early Tender Offer Consideration for each U.S.$1,000 principal amount of Notes validly tendered on or prior to the Early Tender Deadline and accepted for purchase pursuant to the Tender Offer shall be U.S.$920.00, which includes the Early Tender Offer Premium (as defined in the Offer to Purchase) of U.S.$50.00 per U.S.$1,000 principal amount of Notes accepted for purchase.

Pursuant to the terms of the Tender Offer, the Company has elected that the settlement date for the Notes tendered on or prior to the Early Tender Deadline and accepted for purchase is expected to be December 20, 2023, unless extended by the Company (the "Final Payment Date"). Holders will also receive with respect to any Notes validly tendered and accepted for purchase accrued and unpaid interest on such Notes from, and including, the last interest payment date applicable to such Notes to, but not including, the Final Payment Date.

The Tender Offer will remain open until 5:00 p.m., New York City time, on December 14, 2023, unless extended by the Company (the "Expiration Deadline"). The settlement date for the Notes tendered after the Early Tender Deadline and on or prior to the Expiration Deadline and accepted for purchase is expected to be the Final Payment Date.

Amendments to the Tender Offer

The Company hereby announces that it has amended the terms of the Tender Offer, such that the Late Tender Consideration is now equal to the Early Tender Offer Consideration (including, for the avoidance of doubt, the Early Tender Offer Premium). As such, Holders whose Notes are validly tendered after the Early Tender Deadline but on or prior to the Expiration Deadline and accepted for purchase will receive U.S.$920.00, which includes the Early Tender Offer Premium (as defined in the Offer to Purchase) of U.S.$50.00 per U.S.$1,000 principal amount of Notes accepted for purchase. The terms and conditions of the Tender Offer, as set forth in the Offer to Purchase, otherwise remain unchanged.

Questions and requests for assistance in connection with the Tender Offer should be directed to the Lead Dealer Managers:

The Co-Dealer Managers in connection with the Tender Offer are:

Questions and requests for assistance in connection with tendering Notes and participating in the Tender Offer and the submission of a Tender Instruction should be directed to the Information and Tender Agent:

Information and Tender Agent

Morrow Sodali Limited 29/F. No. 28 Stanley Street Central Hong Kong Telephone: +852 2319 4130 103 Wigmore Street London W1U 1QS United Kingdom Telephone: +44 20 4513 6933 333 Ludlow Street South Tower, 5 th Floor Stamford, CT 06902 United States Telephone: +1 203 658 9457 Email: tullowoil@investor.morrowsodali.com

Electronic copies of all documents related to the Tender Offer will be available from the website of the Luxembourg Stock Exchange, the London Stock Exchange and/or online via the Tender Offer Website at https://projects.morrowsodali.com/tullowoilSUN until the consummation or termination of the Tender Offer.

This announcement is being made on behalf of Tullow by Adam Holland, Company Secretary.