Authoritative Sources
Since the official "FPS Procedures and Technical Specifications" document is restricted to scheme participants, this project aggregates data from publicly available documentation provided by directly-connected settlement banks and technology partners.
LHV Connect - Faster Payments Reject & Return Codes
The most comprehensive public list of FPS numeric (REJ) and string (RET) codes, updated for 2025/2026.
https://lhv.com/en/connect/faster-payments-rejection-codesClearBank Developer Portal
Detailed webhook and status documentation for UK Faster Payments, mapping scheme responses to actionable states.
https://clearbank.github.io/docs/faster-paymentsStarling Bank API Reference
Provides numeric scheme codes used in their sandbox environment to simulate payment rejections.
https://developer.starlingbank.com/docs#domestic-paymentsForm3 Technical Documentation
Outlines the implementation of UK Faster Payments returns and rejections following Pay.UK / ISO 20022 standards.
https://www.api-docs.form3.tech/api/schemes/fps-direct/Pay.UK - Faster Payments Service Principles
The official high-level governing document for the Faster Payments Service in the UK.
https://www.wearepay.uk/what-we-do/payment-systems/faster-payment-system/