An open banking API is a standardized interface that allows licensed third-party providers (TPPs) to access bank account information and initiate payments on behalf of customers, with their explicit consent. Banks expose these APIs under regulations such as PSD2 in Europe, the UK Open Banking Standard, or market-driven standards like FDX in the US.

Open banking APIs typically support two main service types: Account Information Services (AIS), which read balances and transactions, and Payment Initiation Services (PIS), which initiate bank-to-bank payments. Access is secured via OAuth 2.0 or similar authorization flows, so the customer authorizes the TPP without sharing online banking credentials.

The Open Banking Tracker maps 50,000+ banks and their API coverage, plus API aggregators that offer a single integration to many banks. For a full overview, see our Open Banking API guide and API aggregators directory.