Crossroads Well, Garvin County, Oklahoma, Update

15 May 2026

This announcement contains inside information for the purposes of Article 7 of the Market Abuse Regulation (EU) 596/2014 as it forms part of UK domestic law by virtue of the European Union (Withdrawal) Act 2018 ("MAR"), and is disclosed in accordance with the Company's obligations under Article 17 of MAR.

Union Jack Oil plc

("Union Jack" or the "Company")

Crossroads Well, Garvin County, Oklahoma, USA Update

Union Jack Oil plc (AIM: UJO), a UK and USA focused onshore hydrocarbon, production, development, exploration and investment company, is pleased to announce a positive update on the Crossroads Well, located in Garvin County, Oklahoma USA. Union Jack holds a 43% interest in this well.

· Crossroads drilled on budget to Target Depth of 4,600 feet

· Electric logs have been acquired and several zones of interest and test intervals have been identified

· Production casing will be run and cemented

· The technical team at Reach Oil and Gas Company Inc., the Operator, has informed Union Jack that the evaluation and testing will begin in mid-June

The Crossroads well encountered good hydrocarbon shows at several levels from the Hoxbar down to the Basal McLish intervals.

Based on a petrophysical evaluation of the downhole logs, four intervals with production potential will be tested. These intervals are the Middle McLish, Basal McLish, Cisco and Hoxbar Sandstones.

David Bramhill, Executive Chairman of Union Jack, commented: "We look forward to the evaluation and test results from Crossroads which has excellent upside potential. Nearby wells that are down-dip from the Crossroads location have produced hydrocarbons.

"We look forward to reporting on evaluation and test results from Crossroads in due course."

For further information, please contact:

Union Jack Oil plc [email protected]

David Bramhill

SP Angel Corporate Finance LLP +44 (0)20 3470 0470

Nominated Adviser and Joint Broker

Matthew Johnson

Richard Hail

Jen Clarke

Zeus Capital Limited +44 (0)20 3829 5000

Joint Broker

Antonio Bossi

Simon Johnson

George Duxberry

Gneiss Energy Limited + 44 (0)20 3983 9263

Financial Adviser

Jon Fitzpatrick

Harbour Access +1 (475) 477 9402

USA Investor Relations

Jonathan Paterson