IBAN Validator
An IBAN validator checks an International Bank Account Number using the ISO 13616 mod-97 checksum — the same algorithm banks use — not just a length or format check, so it catches typos a simple regex would miss. The mod-97 check digit is deliberately designed to catch the two most common ways someone mistypes a long number — a single wrong digit and two adjacent digits swapped — which is exactly why it is stronger validation than simply checking that an IBAN is the expected length for its country.
Educational estimate only. Results are not medical, legal, or financial advice. Confirm important decisions with a qualified professional.
How it works
- Enter an IBAN, with or without spaces.
- Read whether the checksum is valid and the country code.
Formula Rearrange (move first 4 chars to end), convert letters to numbers (A=10...Z=35), check mod 97 = 1
Frequently asked questions
Does a valid checksum mean the account exists?
No — it only confirms the IBAN is correctly formed (no typos). It does not verify the account is real or open; only the bank can confirm that.
What is the mod-97 check?
A checksum defined in ISO 13616: the IBAN is rearranged and converted to a number, and a valid IBAN always leaves remainder 1 when divided by 97 — this catches almost all single-character typos and transpositions.
Which countries use IBAN?
Most of Europe plus many other countries worldwide use the IBAN standard; the US, Canada, and a few others do not.
Is my IBAN sent anywhere?
No. Validation runs entirely in your browser.
Can I validate more than one IBAN at a time?
No — this checks one IBAN per lookup. Paste each one in turn to validate a list.