IBAN Validator
Validate an IBAN's ISO 7064 MOD97-10 checksum — the same algorithm every bank uses.
This checks the checksum and format only — it confirms the IBAN is well-formed, not that it belongs to a real, open account. Never enter a real IBAN here or anywhere outside your bank's own systems.
Checksum result
Valid IBAN
For informational and educational purposes only — not professional or technical advice, and not a substitute for consulting a qualified professional about your specific situation. TrueMeasureKit is not liable for decisions made based on these results. See our Terms of Service.
How MOD97-10 catches a mistyped digit
Every IBAN's first four characters — a 2-letter country code and 2 check digits — get moved to the end, each letter in the whole string is converted to a two-digit number (A=10 through Z=35), and the entire result is treated as one enormous integer and reduced modulo 97. A valid IBAN always leaves a remainder of exactly 1. Because the check digits were calculated to make that true for the correct account number, a single mistyped digit almost always breaks the remainder — which is precisely why banks accept IBANs at all: the checksum catches the vast majority of data-entry errors before a payment is even sent.
Frequently asked questions
What is the MOD97-10 checksum this validator checks?
An ISO 7064 algorithm every valid IBAN's check digits satisfy — rearranging the IBAN and running it through a modulo-97 calculation should always produce a remainder of 1. It confirms structural validity, not that the account itself exists or is active.