How to use

This tool validates IBANs using the standard rearrange + MOD 97 checksum and (when known) the official country length.

Paste one IBAN (or multiple IBANs, one per line) into the input box.
Click Validate.
Review Status, Reason (if invalid), and the Normalized/Formatted IBAN.
Use Copy output to copy the results.

FAQ

What does IBAN validation check?

It checks the IBAN’s structure (country code, check digits), country-specific length (when known), and the MOD 97 checksum.

Does a valid IBAN mean the account exists?

No. Validation only confirms the number is internally consistent; it can’t confirm the account is open or able to receive funds.

What is the MOD 97 rule?

The IBAN is rearranged, letters are converted to numbers (A=10…Z=35), and the result must have remainder 1 when divided by 97.

Why does the tool say “length mismatch”?

Many countries have a fixed IBAN length; if the input length doesn’t match that country’s standard, it’s invalid (with strict length enabled).

Can I validate multiple IBANs at once?

Yes—paste one IBAN per line (or separated by commas/semicolons) and click Validate to get a report for each.

What’s the difference between “normalized” and “formatted”?

Normalized removes spaces/punctuation and uppercases; formatted groups the IBAN into blocks of 4 characters for readability.

Is my data sent to a server?

No. This tool runs locally in your browser and does not perform network requests.