IBAN Validator (International Bank Account Number Checker)

Free IBAN validator that checks the ISO 13616 checksum and country-specific length in your browser. Breaks the IBAN down into country code, check digits, and BBAN. Nothing is sent to a server.

What is the IBAN Validator?

The IBAN Validator checks whether an International Bank Account Number is correctly formatted, using both the ISO 13616 checksum (MOD-97) and the fixed length defined for each issuing country. It also breaks the number down into its country code, check digits, and BBAN (domestic account part) for easy reading.

A single mistyped digit when copying an IBAN into a wire transfer form can lead to a rejected payment or a costly delay in getting the funds returned. Running the checksum through this tool before you submit a transfer catches obvious typos early. Everything runs in your browser, and the IBAN you enter is never sent anywhere.

How to use it

Enter the IBAN Paste it with spaces or hyphens, or as one unbroken string — both work.
Check the result The checksum and length verdict appear immediately, along with the country code, check digits, and BBAN breakdown.
Read the error detail If it's invalid, the tool tells you which check failed: character set, format, length, or checksum.
Try another IBAN Use the clear button to reset the field and check a different number.

Tips for getting more out of it

You can paste an IBAN with spaces or hyphens exactly as you received it — they're stripped automatically before validation.
A "valid" result only means the checksum and length follow the IBAN rules; it doesn't confirm the account actually exists. Always verify the account holder's name through a trusted channel before sending money.
The BBAN (domestic account part) holds the bank code, branch code, and account number in a format that varies by country. If a transfer form only asks for the BBAN, you can copy that field directly.
Countries such as the US, Canada, Australia, and Japan don't use IBAN at all. Transfers to those countries instead rely on a SWIFT/BIC code together with a local account number.
A handful of country codes (like Kosovo) aren't part of the official ISO 3166-1 country list, so the country name may show as unrecognized — that doesn't affect whether the IBAN itself is valid.

Use cases

Double-check before an international wire transfer

Verify an IBAN you received from a counterparty or landlord before entering it into your bank's transfer form.

Accounts payable checks on invoices

Confirm that the IBAN printed on an incoming invoice is structurally valid before it reaches the payment run.

Reference for building your own IBAN validation logic

Use it to check the expected behaviour of a MOD-97 checksum implementation you're building into a form or backend.

See exactly how an IBAN is structured

Break a real IBAN down into its country code, check digits, and domestic account number to understand the format.

Glossary

IBAN: International Bank Account Number — a globally unique identifier for a bank account, made up of a country code, check digits, and the domestic account details (BBAN).
ISO 13616: The international standard that defines the structure of an IBAN and how its checksum is calculated.
Check digits: The two digits right after the country code in an IBAN, used to catch typos. They're calculated using the MOD-97 algorithm.
BBAN: Basic Bank Account Number — the part of the IBAN left after removing the country code and check digits. It holds the bank code, branch code, and account number, with a format that varies by country.
MOD-97: The checksum method that treats the whole IBAN as one large number and divides it by 97. A valid IBAN always leaves a remainder of exactly 1.
SWIFT/BIC code: A code that identifies a specific bank internationally. Where an IBAN identifies an account, a SWIFT/BIC code identifies the bank that holds it.

Frequently asked questions

An IBAN uniquely identifies a specific bank account — it's built from a country code, check digits, and the domestic account details (BBAN). A SWIFT/BIC code identifies the bank itself, and the same code is shared across all of that bank's branches and accounts. International transfers typically require both: the IBAN for the destination account, and the SWIFT code for the bank that holds it.

This tool only checks whether the checksum and length follow the IBAN specification. Whether the account actually exists, is active, or is able to receive funds can only be confirmed by the receiving bank's own systems.

No. Roughly 90 countries and territories, mostly in Europe, the Middle East, and parts of the Caribbean, use IBAN. The US, Canada, Australia, Japan, China, and India are among the countries that don't — transfers there use a SWIFT code together with a local account number and bank code instead.

BBAN stands for Basic Bank Account Number — it's everything left in the IBAN after removing the two-letter country code and two-digit check digits. It contains the bank code, branch code, and account number, and its exact length and structure varies by country.

No. All validation runs entirely in your browser's JavaScript, and nothing is transmitted to an external server.

Side Note — why the last two digits of a country code are called "check digits"

The two digits right after the country code in an IBAN are called check digits, and they aren't part of the account number at all — they exist purely to catch typos. Under the ISO 13616 standard, those two digits are calculated with an algorithm called MOD-97 so that the entire number, including the country code, check digits, and account details, always leaves a remainder of exactly 1 when divided by 97.

Thanks to this design, a single mistyped digit almost always breaks the checksum, and the IBAN comes back as invalid. Banks and payment systems run this same check before processing a transfer, so it acts as a first line of defense against money being sent to the wrong account by accident.

IBAN was standardized across Europe in 1997 and today is used by close to 90 countries and territories, spanning Europe, much of the Middle East, and several Caribbean nations. The US, Canada, Australia, and Japan, among others, never adopted it — transfers to those countries instead identify the destination through a combination of bank code, branch code, and account number (a routing number, in the US). That's why international transfer forms often ask for "an IBAN or a SWIFT code": it's a way of covering both groups of countries at once.

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