GOV.UK Pay API vs Frankfurter

Same instrument, two spec sheets — measured, not claimed.

Uptime · 30d
Uptime · 90d—%—%
Uptime · 30d—%—%
P50 · ms
P95 · ms
AuthapiKeynone
CORSnoyes
HTTPSyesyes
Card requirednono
Commercial useunclearyes
Data licenseUnverifiedPublic data (ECB reference rates)
Free tierFree tier — API key requiredUnlimited — abuse-rate-limited only
Rate limitUnpublishedUnpublished, generous
In directory since2026-07-052026-05-02
operationalpartialdownno data

GOV.UK Pay API vs Frankfurter: common questions

Which is more reliable, GOV.UK Pay API or Frankfurter?

Only Frankfurter is on our probe schedule so far (—% uptime over 90 days). The other is catalogued but not yet live-checked, so we can't compare measured reliability head-to-head — check the uncovered API's own status page for now.

Do GOV.UK Pay API and Frankfurter need an API key?

Frankfurter needs no key, while GOV.UK Pay API requires a free API key. If you want to start calling without signup, reach for Frankfurter first.

Can I call GOV.UK Pay API and Frankfurter from the browser?

Only Frankfurter is browser-friendly — it returns CORS headers over HTTPS. GOV.UK Pay API needs a server-side call or proxy, so factor that into which one fits a front-end project.

Are GOV.UK Pay API and Frankfurter free for commercial use?

GOV.UK Pay API has unclear commercial terms, and Frankfurter allows commercial use on its free tier. We track service terms and the data license as separate fields — see the Commercial use and Data license rows above, and confirm both before shipping either in a paid product.