IBAN Validator
Validate and format IBANs with the mod-97 check.
- Country
- GB
- Check digits
- 82
- Formatted
- GB82 WEST 1234 5698 7654 32
How to use
- 1 Paste the IBAN, with or without spaces.
- 2 Read the valid / invalid result instantly.
- 3 Check the detected country and check digits.
- 4 Copy the neatly formatted IBAN.
About IBAN Validator
The IBAN Validator checks whether an International Bank Account Number is structurally correct and passes the ISO 7064 mod-97-10 checksum that every valid IBAN must satisfy.
Paste a number with or without spaces, in any case, and the tool extracts the two-letter country code and the two check digits, verifies the length against the country's known IBAN profile, and then runs the mod-97 calculation digit by digit to confirm the checksum.
It also reformats the IBAN into the conventional groups of four characters that are easier to read and transcribe.
This catches the most common data-entry mistakes — a transposed digit, a missing character, or the wrong country length — before a payment is ever submitted, saving the delays and fees that bounced transfers can cause.
It is handy when building or testing payment forms, reconciling statements, or simply double-checking an account number someone has sent you.
The check is purely mathematical and offline: it confirms the number is well-formed, not that the account actually exists.
Everything runs locally, so the IBAN you enter is never transmitted to any server.
FAQ
Does a valid result mean the account exists?
No. The check confirms the IBAN is correctly formed and passes its checksum, not that a real, open account is behind it.
How does the validation work?
It applies the ISO 7064 mod-97-10 algorithm: move the first four characters to the end, convert letters to numbers, and check the remainder mod 97 equals 1.