IBAN Validator: Check an IBAN Before You Send Money

A payment that bounces because of one wrong digit costs time, and sometimes a fee. An IBAN contains a built-in checksum, which means most typing mistakes can be caught before the money leaves your account. The IBAN Validator performs that check in seconds.

#What an IBAN actually contains

An International Bank Account Number is not random. It is built from a few identifiable parts:

1. Country code — two letters, such as DE for Germany or NL for the Netherlands.
2. Check digits — two digits calculated from the rest of the number.
3. Bank code — identifies the bank, and its length depends on the country.
4. Account number — the customer's account at that bank.

The total length is fixed per country, which is why an IBAN that is valid in one country can be the wrong length in another.

#How the validator checks an IBAN

The tool performs three checks:

• Country code and length — the input must match a known country format.
• Checksum — the mod-97 calculation that catches transposed or mistyped digits.
• Formatting — spaces and lowercase letters are accepted and normalised.

If any check fails, the tool tells you what is wrong rather than simply rejecting the input.

#What a valid IBAN does not tell you

This is the important limitation. A valid IBAN is correctly formed, not necessarily open and owned by the person you think. The checksum cannot tell you:

• whether the account exists,
• whether it is still active,
• who owns it,
• whether the name matches.

For a large or first-time payment, confirm the account name with the recipient through a channel you already trust, and use your bank's own verification where available.

#Common IBAN mistakes

• Dropped or added characters while copying from an email.
• Transposed digits — the checksum catches most of these.
• Spaces in the wrong place — harmless for validation, but some forms reject them.
• Using a BIC/SWIFT code as an IBAN — they are different things.
• Mixing up two countries — a valid-looking number may still be the wrong length for its country.

#A sensible payment checklist

1. Paste the IBAN into the IBAN Validator and confirm it passes.
2. Read the formatted result back against the source, character by character, for a large payment.
3. Confirm the account holder's name with the recipient.
4. Keep the confirmation with your payment records.

#Frequently asked questions

Is a valid IBAN guaranteed to work? No. It is correctly formed, but the account may be closed or the details may belong to someone else.

Does the tool store the IBAN? The value is used only to run the check.

Can I check a BIC or SWIFT code? No, this tool validates IBANs. BIC/SWIFT codes use a different format.

Are spaces and lowercase allowed? Yes. They are normalised before validation.

Can I use it for SEPA payments? Yes. SEPA uses IBANs, and a checksum failure is a strong sign the details are wrong.