IBAN Validator & Checker

What a valid result actually means

An IBAN validator checks three things: the country code is recognised, the character count matches that country's format and the MOD97 checksum passes. A successful result means the number is structurally possible. It does not confirm the account holder, balance or current account status.

During an IBAN check, the first four characters move to the end, letters are converted to numbers and the resulting sequence is tested modulo 97. A remainder of 1 passes. This catches most transposed or mistyped characters without contacting a bank.

Length is country-specific

There is no single answer to how many digits in an IBAN. The United Kingdom and Germany use 22 characters, France uses 27, Spain 24 and the Netherlands 18. The ISO 13616 registry allows a maximum of 34 characters, while each participating country fixes its own exact length.

Spaces only make the number easier to read and are removed before validation. Lowercase letters are converted to uppercase. Punctuation is rejected because it is not part of the electronic format.

Decoding the national account section

An IBAN decoder reads the BBAN after the country code and check digits. In a UK IBAN it separates the four-letter bank identifier, six-digit sort code and eight-digit account number. A German number contains an eight-digit bank sort code followed by a ten-digit account number. France includes separate bank and branch fields.

To find account number from IBAN, the decoder must use the layout registered for that country. The account field therefore does not start at one universal position. Where the format defines an IBAN branch code, it is displayed separately; otherwise a branch cannot be inferred reliably.

What an IBAN lookup cannot reveal

An IBAN lookup can expose a bank identifier, but a raw identifier is not always enough to return a current institution name. National directories and merger records change independently of the checksum. The tool never claims to perform an account-holder search.

An IBAN checker cannot recognise a fraudster using a real, mathematically valid account. If payment instructions have changed, confirm the recipient and number through a known phone number, contract or another trusted channel before authorising the transfer.

Privacy and practical comparison

The calculation runs in your browser; the entered number is not submitted to a bank. Still, avoid leaving full payment details on a shared computer or in a public screenshot.

Compare the grouped output with the invoice or banking screen four characters at a time. If one character differs, request the details again instead of trying to repair the check digits yourself.