๐ฆ IBAN Validator
Enter an IBAN (International Bank Account Number) to validate its format using the ISO 13616 MOD-97 checksum algorithm.
How to use
- Enter the IBAN to validate (spaces are ignored automatically).
- The validation result (valid/invalid) is shown, along with a formatted display and country code if valid.
How the calculation works
An IBAN (International Bank Account Number), defined in ISO 13616, identifies a bank account across borders. It consists of a two-letter country code, two check digits and a country-specific account number (BBAN). This tool checks, in order: 1. Format: two letters, two digits, then letters and digits. 2. Country and length: the country must be in the SWIFT IBAN Registry and the IBAN must have that country's length (for example 22 characters for Germany and the UK, 27 for France). 3. Check digits (MOD-97-10): move the first four characters to the end, replace letters with numbers (A = 10, B = 11 โฆ Z = 35), and the resulting large number must leave a remainder of 1 when divided by 97. The check-digit scheme catches virtually all single-character typos and swaps of two adjacent characters.
Worked example
Input: GB82 WEST 1234 5698 7654 32 Length: 22 characters (as required for the UK) Rearranged: WEST12345698765432GB82 Letters to numbers: W = 32, E = 14, S = 28, T = 29, G = 16, B = 11 Remainder mod 97: 1 โ valid Changing the last digit (โฆ7654 33) no longer leaves a remainder of 1, so it is invalid.
Things to be aware of
- This tool checks only the format and check digits. Only the bank can confirm that an account actually exists.
- Japan and the US do not use IBAN, so their account numbers cannot be validated here.
- IBANs are usually printed in groups of four characters, but online forms often want them without spaces.
FAQ
What is an IBAN?
International Bank Account Number โ a standardized format used to uniquely identify a bank account for international transfers.
What algorithm does this use?
The MOD-97-10 checksum algorithm defined by ISO 13616. It rearranges the country code and account details into a numeric string, and the IBAN is valid if that number mod 97 equals 1.
Can this confirm a real bank account exists?
No. This tool only validates the IBANโs format (checksum). Only your bank can confirm whether an account actually exists.
Do Japanese bank accounts have IBANs?
No. Japan does not use IBAN, so Japanese accounts have no IBAN. International transfers to Japan use the bank's SWIFT (BIC) code plus the branch and account numbers.