IBAN Validator
The mathematical checksum (modulo 97) is checked, not whether the account exists. No data transmission.
Understanding the IBAN checksum
Every IBAN contains a two-digit check number that helps detect typos. The validator applies the standard method (modulo 97 per ISO 7064) and instantly reports whether the IBAN is mathematically consistent.
- Modulo 97: The first four characters are moved to the end, letters converted to numbers, and the remainder of division by 97 is computed – it must equal 1.
- What is checked: Format, length and checksum. It does not check whether the account actually exists.
- Privacy: The calculation runs locally in the browser.