What Is an IBAN? A Complete Guide for International Transfers
An IBAN (International Bank Account Number) is a standardised way to identify bank accounts across borders. Learn what it is, how it works, and when you need one.
What Is an IBAN?
An International Bank Account Number (IBAN) is a standardised format for identifying bank accounts across national borders. It was developed by the International Organisation for Standardisation (ISO) and the European Committee for Banking Standards (ECBS) to simplify cross-border payments and reduce errors in international wire transfers.
Before IBANs, banks in different countries used incompatible account number formats, leading to frequent errors, delays, and failed payments. The IBAN system solved this by creating a single universal format that works across 77 countries.
What Does an IBAN Look Like?
An IBAN starts with a two-letter country code, followed by two check digits, and then the Basic Bank Account Number (BBAN) — which varies in length and structure by country. For example:
- Germany: DE89 3704 0044 0532 0130 00 (22 characters)
- United Kingdom: GB29 NWBK 6016 1331 9268 19 (22 characters)
- France: FR76 3000 6000 0112 3456 7890 189 (27 characters)
You can decode any IBAN instantly using our free tool to see its country, bank, and account components.
When Do You Need an IBAN?
You need an IBAN whenever you send or receive money internationally within the IBAN system. This includes paying overseas suppliers, receiving salary from a foreign employer, or transferring funds to a family member abroad. Banks in SEPA countries require IBANs for all euro transfers, even domestic ones.
How Is an IBAN Validated?
Every IBAN contains two check digits (positions 3–4) that allow anyone to verify the number has not been mistyped. The validation uses a MOD-97 checksum algorithm — rearranging the IBAN and performing modular arithmetic to confirm the result equals 1. Our tool performs this check automatically.