Britain's biggest banks, defence primes, and telecoms are betting on a three-year-old startup to end their dependence on American AI — TFN

Cosine, the UK government-backed AI startup, has assembled a coalition of major British institutions, including BT, Babcock International Group, Lloyds Banking Group, LSEG, NatWest Group, PwC, Thales UK, and Telefónica Tech UK&I, to co-design Lumen Sovereign, a frontier AI model to be trained entirely on British soil.

The model will run on Isambard-AI, one of Europe’s most powerful supercomputers, using compute awarded through the UK government’s £500M Sovereign AI programme, with deployment readiness targeted for the end of 2026.

For Cosine’s coalition partners, the proposition is simple: OpenAI and Anthropic are outstanding products, and for some of their most sensitive workflows, legally off the table.

Cosine has signed memoranda of understanding with some of the UK’s largest institutions to co-design Lumen Sovereign, a frontier AI model that will be trained entirely on UK infrastructure, deployed within customers’ own environments, and carry no dependence on foreign technology at any stage.

The coalition spans defence, finance, telecoms, and professional services. Babcock International Group, BT, Lloyds Banking Group, LSEG, NatWest Group, PwC, Thales UK, and Telefónica Tech UK&I have all signed on for the design phase.