The IBAN tool normalizes the input to electronic form, then checks the two-letter country code, two check digits, the registered national length, and the ISO 13616 MOD 97 checksum.

For high-use formats where the SWIFT Registry explicitly publishes field positions, it also extracts the bank identifier from the BBAN. Countries such as the United Kingdom and Spain can also expose a branch identifier when the Registry explicitly defines that position.

1. 01Enter an IBAN with or without spaces.
2. 02Review the country code, expected length, actual length and MOD 97 result.
3. 03Where the national structure is implemented, inspect the BBAN, bank identifier and branch identifier.
4. 04Use the result as a format check; real account status still belongs to the bank or payment service.

The first four IBAN characters are the country code and two check digits. Validation moves those four characters to the end, converts letters using A=10 through Z=35, and evaluates the resulting number modulo 97. A standard-conforming IBAN produces a remainder of 1.

Total length and BBAN structure are not globally fixed. National standards bodies or central banks register national formats in the ISO 13616 Registry maintained by SWIFT.

• A passing MOD 97 check and national length only show that the identifier is internally consistent. They do not prove the account exists, identify its owner, show a balance or guarantee it can receive funds.
• The length table prioritizes Europe/SEPA and other common IBAN countries; newly registered formats can be added independently.
• Bank and branch fields are shown only for countries whose published Registry positions are explicitly implemented.
• The tool does not query BICs, account-holder names or live bank systems.

• Catch IBAN transcription errors before form submission.
• Normalize spacing and read country codes during reconciliation or migration.
• Test a payment application's MOD 97 implementation with known examples.
• Extract Registry-defined bank or branch identifiers when available.

IBAN parsing runs entirely in the browser and does not upload account numbers. An IBAN is sensitive financial information; use your own, authorized or test data and avoid publishing complete account identifiers.