An IBAN is the international standard for bank account numbers: a 2-letter country code, 2 check digits, and the national account number (the BBAN), up to 34 characters in total. For example, a German IBAN looks like DE89 3704 0044 0532 0130 00.
Checking an IBAN is mostly mathematics. The two check digits are computed with the MOD-97 algorithm: move the first four characters to the end, replace letters with numbers (A=10, B=11...), and the result must leave a remainder of 1 when divided by 97. If it does, the IBAN is structurally valid — which catches the vast majority of typos and copy errors before money moves.
Check an IBAN in 3 steps
- Open the faymox IBAN Validator.
- Paste the IBAN (spaces are fine, they are stripped automatically).
- Get an instant valid/invalid verdict, with the country, length, and checksum breakdown.
FAQ
What does an IBAN look like?
Up to 34 letters and digits, starting with a 2-letter country code (DE, FR, GB...) followed by 2 check digits and the bank-specific account number. It is usually printed in groups of four for readability.
What does the validator actually verify?
Three things: the country code is valid, the length matches that country's IBAN format, and the MOD-97 checksum passes. That catches nearly all transcription errors.
Is it safe to check an IBAN on a website?
The check runs entirely in your browser — nothing is uploaded or stored. An IBAN on its own cannot be used to withdraw money, but keep full bank details private regardless.