A Dutch account
Input NL91 ABNA 0417 1643 00
Result Valid, Netherlands, 18 characters as expected, BBAN ABNA0417164300.
IBAN Validator
Money & BusinessValidate an IBAN with the official mod-97 checksum, see the country, expected length and a grouped format. Nothing leaves your browser.
Your inputs
Result
Result
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- Country —
- Check digits —
- Characters entered —
- Standard length —
- BBAN account part —
- Grouped format —
Change any input and the result updates instantly.
Formula and rules
- Remove spaces and uppercase the string, then move the first four characters to the end.
- Replace each letter with two digits: A = 10, B = 11, and so on up to Z = 35.
- Read the result as one integer and divide it by 97; a valid IBAN leaves a remainder of 1.
- Check digits = 98 − (country code and BBAN converted the same way, modulo 97).
- Each country fixes its total length, from 15 characters in Norway to 33 in Russia.
Worked examples
A British account
Input GB82 WEST 1234 5698 7654 32
Result Valid, United Kingdom, 22 characters, shown as GB82 WEST 1234 5698 7654 32.
One digit changed
Input NL91 ABNA 0417 1643 01
Result Invalid checksum. The length and country are fine, but the mod-97 remainder is not 1.
FAQ
Does a valid IBAN prove the account exists?
No. The check only confirms that the format and check digits are consistent. Whether the account is open, and whether it belongs to the person you are paying, still has to be confirmed by the bank.
Why is my bank IBAN rejected here?
The usual causes are a missing character, a hyphen or slash that is not part of the IBAN, or copying the domestic account number instead of the full international one. Spaces are ignored, so they never cause a failure.
Is the IBAN I paste sent to a server?
No. The whole check runs in JavaScript on your own device, and closing the tab clears the value. No network request is made with the number.
Which countries use IBAN?
Mainly Europe, including the 40-plus SEPA countries, plus a number of Middle Eastern, North African and Caribbean territories. The United States, Canada and Australia use domestic routing, sort or BSB numbers instead.
Disclaimer: This tool is an estimate based on published rates and common rules. Fees, tax rates and platform policies change often, and the result is not tax, financial or legal advice. Always confirm with official sources or a qualified professional.