Mayfair & St James's is home to 15 of London's best tech companies, led by Fintech (4).

Savings platform letting people and businesses hold cash across hundreds of accounts from 65+ banks in one place.

Platform that lets institutions invest cash in fixed-term, investment-grade products through one onboarding.

Agentic compliance platform that automates know-your-business checks and continuously monitors business customers for financial services firms.

Merchant of record and tax of record platform that handles local payments, tax and customs so merchants can sell cross-border.

London AI cloud company that builds and runs GPU data centres across Europe and the US.

AI-native procurement platform using AI agents for sourcing, negotiation, intake and spend analytics at large enterprises.

Rezolve AI sells AI-powered product search and conversational commerce software to retailers.

MUBI is a curated film streaming service that also produces and distributes films.

iProov provides face biometric verification that checks a person is real and present when they log in or onboard online.

Security platform that links alerts across a customer's existing tools into cases, with AI triage and a managed 24/7 SOC under human oversight.

Stablecoin payment infrastructure for converting and moving money between fiat and stablecoins across 70+ countries.

Risk ratings and monitoring of crypto exchanges, custodians and lenders so institutions can manage counterparty exposure.

Clinical-stage biotech developing next-generation oral and injectable medicines for obesity and cardiometabolic disease.

London oncology drug developer that in-licenses cancer assets and funds them through clinical trials.

Builds liquid air energy storage plants that store renewable power for long periods and release it to the grid.