For account information (AIS), GoCardless Bank Account Data — the API formerly known as Nordigen — has the most generous free tier in the UK and EEA: free for low volumes of connected end users, with paid plans only when you scale. TrueLayer and Yapily both offer free sandboxes and pay-as-you-go pricing that suits early-stage teams. Plaid has a developer free tier for testing. Tink, Moneyhub, and Salt Edge typically require a sales conversation for pricing.

For pay-by-bank (PIS) and Variable Recurring Payments, expect per-transaction pricing rather than a free tier. UK pay-by-bank typically costs 0.1–0.5% of the transaction or a flat fee of around 5–30p — much cheaper than card schemes (1.5–3.5%). TrueLayer, Yapily, and GoCardless are competitive here. Watch for hidden costs: minimum monthly commits, refresh-frequency tiers (real-time vs cached), identity or income add-ons, and support SLAs.

The Open Banking Tracker API aggregators directory lets you filter by sandbox availability and country, and each profile links to the provider's pricing page where it is public. See best-open-banking-apis-uk for a fuller comparison and which-open-banking-providers-offer-sandbox for free testing options.

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.