IBAN Validator
Check an IBAN’s format and mod-97 checksum, with country/length and checksum shown separately.
About this tool
Paste an International Bank Account Number to check it in two distinct steps: first, whether the country code is recognized and the total length matches what that country’s IBAN format requires, then separately, whether the check digits pass the mod-97 checksum defined by the IBAN standard. Splitting these into separate results matters because they fail for different reasons - a wrong length usually means a digit was dropped or an extra one typed, while a checksum failure with correct length usually means a single digit was transposed or mistyped somewhere in an otherwise correctly-structured number. On success, the IBAN is broken into its country code, check digits, and BBAN (Basic Bank Account Number) so you can see exactly what each segment represents. Covers the common European and EEA IBAN-issuing countries. Runs entirely client-side.
Frequently asked questions
They catch different kinds of mistakes. A country/length mismatch usually means the IBAN was truncated, has extra characters, or the country code itself is wrong - an error you can often spot by eye once it’s called out. A checksum failure on an otherwise correctly-sized IBAN almost always means a single digit was mistyped or two digits were swapped, a much subtler error that the mod-97 calculation is specifically designed to catch. Separating them tells you which kind of mistake to look for.
No - the mod-97 checksum only confirms the IBAN is internally consistent according to the standard’s check-digit formula, the same first-line validation a bank’s own systems would run before ever contacting the account-holding institution. It can’t confirm the account actually exists, belongs to a particular person, or is open, since that information lives only inside the issuing bank’s own systems.
BBAN stands for Basic Bank Account Number - it’s the country-specific part of the IBAN that comes after the country code and check digits, typically encoding the bank code, branch code, and account number in whatever format that country’s banking system uses internally. The IBAN standard wraps this national format with a consistent country code and checksum so it can be validated and processed internationally.
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