Overview
API overview
A single RESTful API covering the full lifecycle of client onboarding, multi-currency accounts, payments, and real-time event notifications. Everything you need to embed banking into your platform.
Technical specifications
How it works
Mercury sits between your platform and the UK/EU payment rails. You make API calls to manage clients and accounts; Mercury handles bank connectivity, compliance, and settlement. Webhooks keep your system in sync in real time.
API domains
22 endpoints organised into six resource domains. Click any domain to jump to the API reference.
Clients
Onboard, update, and retrieve end-clients under your programme. Full KYC lifecycle management.
GBP accounts
Create sterling virtual accounts with dedicated sort code + account number. Query balances, pull statements, block/unblock/close.
EUR virtual IBANs
Create euro virtual IBANs with SEPA connectivity. Full account management, statements, and lifecycle controls.
Payments
Send GBP via Faster Payments (seconds) and EUR via SEPA Credit Transfer (same-day). Return inbound GBP payments.
Confirmation of Payee
Verify beneficiary account details before sending payments. Check SRD requirements for enhanced verification.
Lookup data
Reference data for currencies, countries, business types, risk ratings, and CoP eligibility. Use these to populate dropdowns and validate inputs.
Real-time webhook events
Mercury delivers 26 event types via HTTPS POST to your registered endpoint. No polling required. Your system stays in sync as things happen.
Key concepts
You operate as a distributor with a master account. Your end-clients are onboarded under your programme. You control the full client and account lifecycle via API. Mercury provides the banking rails and regulatory wrapper.
Every request is signed with HMAC-SHA256 using your Secret Key. The signature covers your API key, the request method, path, body, and a unique nonce, protecting against replay attacks and tampering. Learn more →
Two fully isolated environments: Sandbox for integration development and testing, Production for live transactions. Separate credentials for each. Same API surface. Code that works in sandbox works in production.
Don't poll, subscribe. Webhooks fire for every meaningful state change across clients, accounts, and payments. Build reactive integrations that respond to events as they happen.
Typical integration flow
Updated about 3 hours ago