IBAN Validator
Check whether an IBAN is valid using the official mod-97 checksum, entirely in your browser.
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How Is an IBAN Validated?
Every IBAN carries a built-in checksum defined by ISO 13616: the first four characters are moved to the end, letters are replaced by numbers (A=10 … Z=35), and the resulting number must leave a remainder of 1 when divided by 97. This catches virtually all typos — a single wrong digit makes the check fail.
The tool also checks the expected length for the country code (e.g. TR: 26, DE: 22, GB: 22 characters). Validation happens entirely in your browser; the IBAN you type is never sent anywhere. Note that a valid checksum means the number is well-formed — it cannot tell whether the account actually exists.
Frequently Asked Questions
Does a valid result mean the account exists?
No. The mod-97 check confirms the IBAN is structurally correct and free of typos. Whether the account is open and belongs to the intended person can only be confirmed by the bank.
Is my IBAN sent to a server?
No. The checksum is computed with JavaScript in your browser; nothing you type leaves your device.
How long is an IBAN?
It varies by country: Turkey uses 26 characters, Germany 22, the UK 22, France 27. The country code (first two letters) determines the expected length, which this tool verifies.
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IBAN Validator