IBAN structure
An IBAN contains a country code, check digits, and a country-specific bank account structure. The visible format can be checked before using the value in forms or records.
Checksum basics
The IBAN checksum uses a mod-97 style calculation. If the checksum fails, the IBAN is likely mistyped. If it passes, the format is plausible, but that does not prove the account exists or belongs to anyone.
Common mistakes
Do not treat a passing checksum as confirmation of payment eligibility, ownership, balance, identity, or records. Verify important transfers with the appropriate source.
FAQ
Can an IBAN pass checksum and still be unusable?
Yes. Format and checksum checks are not live account checks.
Should spaces matter?
Spaces are often used for readability and can be removed before checking.