Bank account checksum validation
We validate the IBAN structure for every country in the directory. For 30 of them, we go a step further: the account number encoded inside the IBAN carries its own check digit, and we verify it too.
One request, four layers of validation
Every call to the validate endpoint runs a stack of checks. Account checksum validation is the most granular of them, and it's applied automatically whenever the destination country supports it, no extra parameter required.
Countries with account-level checksum support
Open a country to see its full IBAN format and browse its banks.
Common questions about account validation
What is bank account checksum validation?
Some countries embed a check digit or checksum inside the account number portion of the IBAN. Validating it confirms the account number itself is well-formed, not just the IBAN as a whole.
Do I need to call a separate endpoint for this?
No. When the IBAN belongs to a supported country, the account checksum result is included automatically in the validate endpoint response, alongside the length, checksum and structure checks.
What happens for countries not on this list?
The IBAN is still validated in full, structure, length and checksum, we just don't perform an additional account-number-level check, since that country doesn't publish a verifiable account checksum rule.
Does a valid checksum guarantee the account exists?
No. A checksum pass means the account number is mathematically well-formed. It doesn't confirm the account is open, active or held by a specific person, only the bank can confirm that.