IBAN Validator
Check whether an International Bank Account Number is valid using the mod-97 checksum and length rules.
Validate an IBAN instantly
The IBAN Validator checks whether an International Bank Account Number is structurally valid. It verifies the format, the country-specific length, and the ISO 7064 mod-97 checksum — the same check banks use to catch typos before a transfer. Everything runs in your browser, so the IBAN you enter is never sent anywhere.
What is an IBAN?
An IBAN (International Bank Account Number) is a standardized way to identify a bank account across borders. It starts with a two-letter country code, followed by two check digits, then the country-specific account details. For example, GB82 WEST 1234 5698 7654 32 is a UK IBAN. The format makes international payments more reliable by encoding a checksum.
How validation works
The clever part is the mod-97 checksum. The first four characters are moved to the end, letters are converted to numbers (A=10 … Z=35), and the resulting huge number is divided by 97. A valid IBAN always leaves a remainder of exactly 1. This catches the vast majority of typos — a single wrong digit will almost always fail the check.
How to use it
- Paste or type an IBAN (spaces are fine).
- See instantly whether it's valid.
- If invalid, the reason (format, length, or checksum) is shown.
What it checks
| Check | What it confirms |
|---|---|
| Format | Two-letter country, two check digits, then account chars |
| Length | Matches the country's expected IBAN length |
| Checksum | Passes the ISO 7064 mod-97 test |
Validity vs existence
A valid IBAN means the number is correctly formed — not that the account actually exists or belongs to a particular person. Only the bank can confirm an account is real and active. Use this tool to catch entry errors before initiating a transfer, which prevents failed or misdirected payments.
Private and free
Validation runs entirely in your browser — your IBAN is never uploaded or stored. The tool is completely free with no sign-up.
Frequently asked questions
How does IBAN validation work?
It checks the format and length, then runs the ISO 7064 mod-97 checksum, which must leave a remainder of 1 for a valid IBAN.
Does a valid IBAN mean the account exists?
No. It confirms the number is correctly formed. Only the bank can verify the account is real and active.
Can I include spaces?
Yes. Spaces are ignored, so you can paste an IBAN in its usual grouped format.
Is my IBAN private?
Yes. Validation runs entirely in your browser and nothing is uploaded.