How to validate an IBAN
Check an IBAN’s country format and mod-97 checksum before sending a payment. Step-by-step, plus a free IBAN validator.
You can catch a mistyped IBAN instantly by checking its country-specific length and its mod-97 checksum — before ever attempting a transfer. Here is how, and what it does and does not prove.
The mod-97 check
Move the first four characters (country code + check digits) to the end, replace each letter with two digits (A=10 … Z=35), and take the big number mod 97. A valid IBAN yields 1. This single test catches almost every typo and transposed character. Each country also has a fixed IBAN length to check against.
What it does not prove
A valid format and checksum do not mean the account is open, active, or belongs to who you think. They only reject typos. For real confirmation you need the bank or a payment provider.
Step by step
Enter the IBAN into the validator (spaces are ignored).
It checks the country code, expected length, and mod-97 checksum.
A pass means the format is correct — safe to submit for a real transfer.
Remember: a valid IBAN is not proof the account exists or is active.
Try it now — free, no signup
Use the IBAN validator in your browser. Then, when you need it at scale with an API key and higher limits, grab the full Eveses API.