Barclays AI 100 names Fractile, Isomorphic Labs as UK AI funding hits £8.3bn

TL;DR:

• Barclays Eagle Labs has launched the inaugural AI 100 ranking, naming Fractile and Isomorphic Labs among Britain’s fastest-growing AI businesses.
• UK AI firms attracted £8.3bn of investment in 2025, a near-trebling on the £2.9bn raised a year earlier; London now headquarters three-quarters of UK AI fintechs.
• A Guardian investigation has separately questioned whether several headline-grabbing AI infrastructure pledges are as substantial as ministers have claimed, with DSIT acknowledging it is not auditing the figures.

Barclays has put a stake in the ground on UK AI with its first AI 100 ranking, published this week through the bank’s Eagle Labs division. The list names Oxford-founded inference-chip startup Fractile — which closed a £165 million (USD $220 million) round last week from Founders Fund, Accel and Factorial Funds — alongside London-based drug-discovery company Isomorphic Labs, which raised £1.65 billion (USD $2.1 billion) earlier this year. The AI 100 cohort has collectively raised £11.3 billion, generates £734 million in annual revenue and employs more than 8,500 people.

A record year for UK AI funding

Eagle Labs’ supporting research found UK AI businesses pulled in £8.3 billion in 2025, a near-trebling on the £2.9 billion raised the year before. London now headquarters almost three-quarters of UK AI fintechs, with much of the capital flowing into the infrastructure layer — compute, software platforms and data architecture — rather than consumer-facing chatbots. Nearly half of all UK AI rounds in 2025 were first-time raises, a sign that the entry pipeline is still expanding even as competition for engineers and capital tightens.

The numbers sit alongside Westminster’s hard pivot on AI capital. The government’s AI Opportunities Action Plan, updated in 2026, sits with the new Sovereign AI Unit charged with stopping prized UK intellectual property from drifting overseas before it can scale. Abdul Qureshi, head of Barclays Business Banking, framed the challenge as one of “turning those breakthroughs into sustainable global businesses.”

Audit questions shadow the celebration

The same week as the Barclays ranking, a Guardian investigation questioned several of the AI investment announcements promoted by ministers as part of the government’s drive to “mainline AI into the veins” of the economy. The Department for Science, Innovation and Technology rejected the substantive claims but acknowledged it was “not playing an active role in auditing these commitments” — including high-profile datacentre pledges linked to Nvidia-backed firms Nscale and CoreWeave, where some projects badged as new sites were in fact expansions inside existing facilities.

For UK SMEs reading the AI 100 as a market signal, the takeaway is two-handed: capital is genuinely flowing into UK AI infrastructure plays at unprecedented scale, but headline announcement numbers warrant a closer look at substance versus rebranding before they become buy-side assumptions.

Looking forward

Eagle Labs has flagged that the North West’s AI ecosystem has expanded faster than London’s since 2019, albeit from a much smaller base. The regional rebalancing, anchored in industrial AI and advanced manufacturing clusters outside the M25, may matter as much to SME founders weighing where to plant their flag as the headline £8.3 billion. Whether the Sovereign AI Unit can keep the next Isomorphic Labs from listing or being acquired abroad is the structural question the ranking sets up but does not answer.