Embedded GBP & EUR banking
One API to onboard clients, open accounts, send payments, and receive real-time notifications across your entire portfolio. Go from sandbox to live in days, not months.
Getting started
Set up credentials, sign your first request, and make your first API call against the sandbox.
Authentication
Step-by-step HMAC-SHA256 signing with examples in Python, Node.js, Java, C#, and C++.
API reference
Complete documentation for all 22 REST endpoints with request and response schemas.
Why Mercury
GBP + EUR from one API
Single integration for sterling and euro. No juggling separate providers or parallel integrations.
Seconds, not days
GBP Faster Payments settle in seconds. SEPA Credit Transfers same-day. API responses in milliseconds.
26 webhook events
Instant notifications for every client, account, and payment event. No polling required.
Built-in Confirmation of Payee
Verify beneficiary names before sending payments. Reduce fraud and misdirected transfers.
FCA-authorised EMI
Client funds safeguarded. Mercury handles regulatory complexity so you can focus on your product.
Modern REST API
Clean RESTful design, HMAC signing, comprehensive error responses, and detailed webhook payloads.
First API call in 4 steps
Sign your request
Generate an HMAC-SHA256 signature from your API key, method, path, body, and nonce.
Guide →Explore and build
Browse the API reference, explore architecture patterns, and start building.
API reference →API capabilities
Clients
Onboard and manage end-clients. Full lifecycle from creation through KYB to closure.
GBP accounts
Open sterling accounts with dedicated sort codes and account numbers. Query balances and statements.
EUR virtual IBANs
Create euro virtual IBANs with SEPA connectivity. Full account management and statement retrieval.
GBP payments
Send and receive GBP via Faster Payments. Real-time settlement notifications via webhooks.
EUR payments
Initiate SEPA Credit Transfers across Europe. Track payment status through to settlement.
Confirmation of Payee
Verify beneficiary account details before payment. Reduce fraud and misdirected transfers.
Webhooks
Real-time notifications for 26 events across clients, accounts, and payments.
Lookup data
Currencies, countries, business types, risk ratings, and CoP reference data.
Sterling payments
Create and manage GBP payment transactions with full status tracking.
Integration guides
Ready to integrate?
Tell us about your integration and the Mercury team will be in touch to set up your sandbox access.