IBAN Validator
Paste an IBAN to check its country-specific length and checksum before you send an international payment.
How IBAN validation works
An IBAN (International Bank Account Number) always starts with a 2-letter country code and 2 check digits, followed by a country-specific number of characters that encode the bank, branch, and account. Each country has a fixed, published IBAN length — for example, German IBANs are always 22 characters, French ones are 27.
This tool checks two things: first, whether the total length matches what's expected for that country's code, and second, whether the built-in checksum is mathematically valid. The checksum uses the ISO 7064 MOD 97-10 algorithm — the same calculation banks themselves run — so a passing result means the IBAN is structurally well-formed, though it doesn't guarantee the account actually exists or is currently open.
Nothing you type is sent anywhere — the check runs entirely in your browser.
Frequently asked questions
Does a valid result mean the bank account definitely exists?
No. It confirms the IBAN is structurally correct — right length, right checksum — which catches the vast majority of typos and copy-paste errors. It can't confirm the account is open or still active; only the receiving bank can verify that.
Why did it say the length was wrong?
Each country has one fixed IBAN length. If your IBAN doesn't match the expected length for its country code, a digit is likely missing or duplicated somewhere.
Why did it say the checksum failed even though the length was right?
The two check digits right after the country code are calculated from the rest of the IBAN using a specific formula. If even one character elsewhere is wrong — a transposed digit, a misread letter — the checksum won't match, even if the total length is correct.
Is my IBAN sent to a server when I check it?
No — the validation logic (length lookup and checksum math) runs entirely in your browser. Nothing you type here is transmitted anywhere.