IBAN validator

The international bank account number (iso 13616) (Europe and 80+ countries). Validation runs entirely on the check-digit algorithm: rearrange, map letters to digits, then mod 97 must equal 1. No external registry is queried, so there is no rate limit and no per-lookup fee.

Result appears here.

What the API returns

GET /v1/identity/validate?type=iban&value=DE89 3704 0044 0532 0130 00

{
  "type": "iban",
  "valid": true,
  "formatted": "DE89 3704 0044 0532 0130 00",
  "details": { ... }
}

Important limitation, stated plainly

A checksum proves the number is well-formed. It does not prove the number was ever issued, nor that it belongs to the person presenting it. Any vendor claiming otherwise from a checksum alone is overselling. Use this to reject the ~90% of bad input that is simply mistyped, then use an official registry for the rest.