Web Development
IBAN Validator
Validate an IBAN against the ISO 7064 (mod 97) checksum, format, and the expected length for its country. Everything runs in the browser.
An IBAN (International Bank Account Number) is an international bank account number format with a built-in checksum under ISO 7064 (mod 97). This tool verifies that checksum, along with the format and length expected for the country encoded in the IBAN.
How to use it
- Paste an IBAN (with or without spaces) — the checksum and format check happen instantly.
- The first two letters identify the country, and the tool checks the number's length against what's expected for that country.
- If validation fails, it tells you exactly what's wrong: length, format, or checksum.
Common uses
- Basic validation of an IBAN field in a payment or vendor-registration form before it hits the backend.
- Quickly checking whether a manually copied account number from a document contains a typo.
- Verifying the format of an IBAN received from a client or partner in another country.
Things to keep in mind
An IBAN that passes the MOD-97 check only confirms the number's structure is correct, not that the account is real or active.
Not every country uses IBAN — some banking systems (the US, for example) have their own separate account number formats.
Article about this tool: IBAN: how an international bank account number is structured
Frequently asked questions
What does the mod-97 checksum actually verify?
It's the ISO 7064 algorithm: the IBAN is rearranged and converted into a number, and that number must leave a remainder of 1 when divided by 97 — this catches typos and swapped characters but doesn't confirm the account exists.
Why does the expected length differ by country?
Each country's national banking format defines a fixed IBAN length, for example Germany uses 22 characters and the United Kingdom also uses 22, so the tool checks the total length against the country code found at the start of the IBAN.
What if my country isn't in the length list?
The checksum check still runs normally; only the length check is skipped for countries missing from the tool's reference table, and that doesn't affect the checksum result.
Do I need a BIC/SWIFT code if I've already entered an IBAN?
For transfers within SEPA — usually no, since the IBAN already contains the bank code within its structure; but some payment systems and transfers outside SEPA still require a separate BIC/SWIFT code as an extra check on the payment's routing.
Does an IBAN that passes the MOD-97 check mean the account actually exists?
No — the checksum check only confirms the number's mathematical structure is correct, not that the account actually exists at a real bank; only the banking system itself, while processing a payment, can ultimately confirm an account exists.