Spudding of the Sark Well Central Oklahoma USA

15 August 2025

Union Jack Oil plc

("Union Jack" or the "Company")

Spudding of the Sark Well Central Oklahoma USA

Union Jack Oil plc (AIM: UJO, OTCQB: UJOGF), a UK and USA focused onshore hydrocarbon, production, development, exploration and investment company is pleased to report, further to the Company's announcement of 9 July 2025, that it has been informed by the Operator, Reach Oil and Gas Inc., that the Sark well, located in Central Oklahoma, USA has been spudded. Union Jack currently holds a 60% interest in the Sark well.

David Bramhill, Executive Chairman of Union Jack, commented: "Following on the heels of the successful producing Moccasin well, the high-impact Sark well is of major importance to Union Jack, both financially and operationally.

"I look forward to reporting on the results of Sark as soon as information becomes available".

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 +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

Paul Weidman

Harbour Access +1 (475) 477 9402

USA Investor Relations

Jonathan Paterson