Change of Name

(Registration Number: 12886458)

Share code on the LSE: MAST

('MED' or 'the Company')

Dated: 3 November 2025

MAST Energy Developments PLC

("MAST" or "MED" or the "Company")

Change of Name

London, UK - Mast Energy Developments PLC (LSE: MAST) is pleased to announce that it has changed its name to Quantum Data Energy PLC (LSE: MAST). Companies House issued a change of name certificate on 3 November 2025 and the name change has become effective immediately.

The Company confirms that the change of name has been notified to the London Stock Exchange and trading in the Company's shares under the new company name is expected to commence at 8.00 a.m. on 4 November 2025. The Company's TIDM, ISIN and SEDOL remain unchanged. Existing share certificates should be retained and will remain valid.

The Company's new website address https://www.quantumdata.energy will be published live before 8.00 a.m. 4 November 2025.

Pieter Krügel, CEO at MAST Energy, said: "Mast Energy Developments PLC is rebranding to Quantum Data Energy PLC - a new identity that reflects the Company's evolution from a UK-focused flexible generation operator into a modular, data-integrated power platform supporting both the national grid and the rapidly expanding AI datacentre sector. The Company continues to operate and expand its existing power assets, while accelerating a new strategy with a vision to deliver 1 GW of AI datacentre power campuses over the next 36 months. Our new name and brand come at an appropriate time following our recent strategic expansion, and better reflect our purpose as we advance toward our new vision."