IBAN Validator

Common questions

Does a valid IBAN mean the account exists?

No, and this is the most important thing to understand. Validation proves the number is internally consistent, meaning it has not been mistyped. Only the receiving bank knows whether the account is real, open, or belongs to the person you think it does. Always confirm a payee through a separate channel before sending money, particularly if bank details arrived by email.

How does the checksum work?

The two digits after the country code are computed from every other character. The whole IBAN is rearranged, letters are replaced by numbers (A is 10 through Z is 35), and the result must leave a remainder of 1 when divided by 97. That single check catches essentially all single-character typos and transposed pairs, which is exactly what it was designed for.

Why are IBANs different lengths in different countries?

Because each country kept its own existing account-numbering scheme and wrapped it in the IBAN format. Norway needs 15 characters, Malta needs 31. The length is fixed per country, so a number that is one character short is invalid regardless of its checksum, and that is checked here before the arithmetic runs.

Can I check a US bank account this way?

No. The United States, Canada, Australia and several other countries do not use IBANs; they use routing and account numbers instead, sometimes with a SWIFT/BIC code for international transfers. This tool covers the countries that issue IBANs and will tell you when a country code is not one of them.

What is the BBAN?

The Basic Bank Account Number, the part after the country code and check digits. Its internal structure varies by country and usually encodes the bank, sometimes a branch, and the account number itself. It is shown here separately so you can compare it against what a bank gave you.

Is my account number uploaded?

No. The whole check is arithmetic that runs in this browser tab. That matters more for this tool than most: bank details are exactly the kind of data that should not be pasted into an unknown website.