An IBAN (International Bank Account Number) is a standardised way to identify a bank account across borders. It was introduced by the International Organization for Standardization (ISO 13616) and is now used by 81 countries — covering virtually all of Europe, the Middle East, and parts of the Caribbean and Central America.

Every IBAN starts with a two-letter country code (e.g. DE for Germany, GB for the UK), followed by two check digits, then the domestic account number in a format specific to that country. The total length ranges from 15 characters (Norway) to 34 characters (Malta).

What is an IBAN used for?

IBANs are required when making international bank transfers — your bank needs the recipient's IBAN to route the payment to the correct account. Within the SEPA zone (36 European countries), IBANs are also used for all domestic euro transfers, direct debits, and instant payments.

Without a valid IBAN, international wire transfers will typically be rejected or returned. If you receive an IBAN from someone, it's worth validating it before initiating a transfer — this tool checks the format and ISO 7064 checksum to catch transcription errors.

How to read an IBAN

Every IBAN has the same structure at the start, then a country-specific BBAN (Basic Bank Account Number):

GB 29 NWBK 601613 31926819

Country (GB) Check digits Bank code Sort code Account number

The check digits (positions 3–4) are calculated using the ISO 7064 MOD-97-10 algorithm. A valid checksum doesn't guarantee the account exists, but it does confirm the number wasn't garbled in transcription.

Does the US use IBAN?

No. The United States, Canada, Australia, China, India, and most Asian and African countries do not use the IBAN system. US bank accounts are identified by a routing number (ABA) and account number. To receive international transfers into a US account, you typically provide a SWIFT/BIC code alongside the routing and account numbers.