Category: Developer tools
IBAN Validator
Validate and format IBANs with the mod-97 checksum
Validate an International Bank Account Number (IBAN) using the ISO 7064 mod-97 checksum, see its country code, and view it formatted in the standard four-character groups. Runs entirely in your browser, without contacting any bank.
Everything on this page is processed in your browser. Nothing is uploaded.
What this tool does
An IBAN encodes a country code, two check digits, and a country-specific bank account identifier. The check digits are computed by moving the first four characters to the end, converting each letter to a two-digit number (A=10 ... Z=35), and confirming the resulting number is congruent to 1 modulo 97. This tool performs that calculation locally; it does not look up the account, the bank, or contact any external service, so it can only confirm the checksum is well-formed, not that the account exists.
How to use it
- Paste or type an IBAN, with or without spaces.
- Read the result to see whether the checksum is valid.
- Check the country code and the formatted version, grouped in fours for easier reading.
Privacy
This tool runs entirely in your browser. Your input is never uploaded, stored or shared — closing the tab removes it.
Frequently asked questions
- Does a valid result mean the account exists?
- No. This tool only checks the mod-97 checksum built into every IBAN. It cannot confirm the account is open, active, or belongs to anyone in particular.
- Is my IBAN sent to a server?
- No. The checksum is calculated entirely in your browser.
- Why are the first four characters moved to the end?
- The ISO 7064 mod-97 algorithm defined for IBANs requires rearranging the string this way before the numeric conversion, so that the country code and check digits are also covered by the checksum.