UK Bank Account Validation API

A single wrong digit in a sort code or account number means a failed payment, a support ticket and a frustrated customer — or worse, money sent to the wrong person. AutoPostcode's bank validation API verifies UK account details the moment they're entered, so payments go through first time.

See it in action

Modulus checks confirm the sort code and account are structurally valid; Confirmation of Payee matches the name.

Two levels of verification

Modulus checking — 1 credit

Instantly confirms that a sort code and account number are a mathematically valid combination using the official UK modulus algorithm. It catches transposed and mistyped digits before any payment is attempted — no bank contact required.

Confirmation of Payee — 10 credits

Pass the account holder's name with cop=true and the API confirms whether it matches the name registered on the account. This is the UK standard for preventing authorised push payment (APP) fraud and misdirected payments, returning a clear match / close match / no match result.

What you get back

• Valid / invalid verdict from modulus checking
• Normalised sort code and account number
• Confirmation of Payee match result (with cop=true)
• Matched account name for close matches
• Personal vs business account handling
• Instant response for inline form validation

Example response

{
  "valid": true,
  "verdict": "valid",
  "sort_code": "070093",
  "account_number": "33333334",
  "confirmation_of_payee": null   // { match, account_name } when cop=true
}

Where teams use it

• Validating bank details at onboarding for direct debits and payouts
• Preventing APP fraud with Confirmation of Payee before sending funds
• Reducing failed payments and payment-return admin
• Verifying supplier and payroll accounts before disbursement

One API key for every check

Bank validation shares a single API key and credit pool with postcode lookup, phone validation and email validation — verify identity, contact and payment details from one integration.