The most widely used open banking APIs in the UK are: TrueLayer (UK & Europe specialist; strongest for pay-by-bank and Variable Recurring Payments), Yapily (infrastructure-only API with no consumer-facing UI; popular with platforms that want to white-label), Tink (Visa-owned, broad UK and European coverage for AIS and PIS), Plaid (UK + global, strong for account data, identity, and income verification), GoCardless (UK and EU bank payments, including the Nordigen-powered Bank Account Data API and Instant Bank Pay), Moneyhub (UK-focused enterprise AIS with strong personal-finance and pensions tooling), and Salt Edge (global coverage including the UK, often chosen by teams that need many regions through one integration).

There is no single 'best' API — choice depends on your use case. For pay-by-bank checkout and VRP, shortlist TrueLayer, Yapily, GoCardless, and Tink. For account data, statements, and lending decisions, look at Plaid, TrueLayer, Tink, and Moneyhub. Other criteria: coverage of the CMA9 plus smaller building societies and neobanks; whether you can rely on the aggregator's TPP licence (so you do not need your own FCA AISP/PISP authorisation); pricing model (per-call, per-user, or flat); and developer experience (sandbox quality, SDKs, docs, and support).

The Open Banking Tracker has a dedicated UK view of its API aggregators directory at /api-aggregators?country=GB, plus the Open Banking Providers guide and a Pay by Bank APIs comparison for payment-initiation use cases. Each provider profile lists UK bank coverage, AIS/PIS support, sandbox availability, and a link to the developer portal so you can shortlist quickly.

For a side-by-side comparison with UK bank counts, AIS/PIS/VRP support, licence model, and pricing, see Open Banking APIs in the UK.