What Is an IBAN?
An IBAN (International Bank Account Number) identifies a specific bank account for international and, in many countries, domestic transfers. It is used across Europe, the Middle East and many other regions. Each IBAN is up to 34 letters and digits long and is built from three parts:
- Country code: two letters, such as DE for Germany, GB for the United Kingdom or TR for Türkiye.
- Check digits: two numbers used to detect typing mistakes.
- BBAN (Basic Bank Account Number): the domestic bank code and account number, in a country-specific format and length.
How the Validator Checks an IBAN
The tool follows the ISO 13616 standard. It removes spaces, checks the country code and expected length (for example 22 characters for Germany and the UK, 26 for Türkiye, 27 for France and 18 for the Netherlands), and then runs the MOD-97 checksum:
- Move the first four characters to the end of the IBAN.
- Replace each letter with two digits (A = 10, B = 11, … Z = 35).
- Divide the resulting number by 97. A valid IBAN leaves a remainder of exactly 1.
What a “Valid” Result Does and Does Not Mean
A valid result means the IBAN is correctly structured and the check digits match, so it almost certainly contains no typing errors. It does not confirm that the account exists, that it is open, or who owns it. Before sending a large payment, confirm the details directly with the recipient through a channel you trust — especially if the account details arrived by email, since fraudsters often send altered bank details.
Privacy
Validation runs entirely in your browser. The IBAN you enter is not sent to any server or stored.
Frequently Asked Questions
Do I need an IBAN to send money to the United States?
No. The US does not use IBANs. US transfers use a routing number (ABA) and account number, and international transfers to the US also need the bank’s SWIFT/BIC code.
What is the difference between an IBAN and a SWIFT/BIC code?
An IBAN identifies an individual account. A SWIFT/BIC code identifies the bank itself. International transfers often ask for both.
Why does my IBAN fail validation?
The most common causes are a mistyped or missing character, a swapped pair of digits, or the letter O typed instead of the number 0. The checksum is designed to catch exactly these errors, so re-copy the IBAN from your bank statement or app.
Can I share my IBAN safely?
Sharing an IBAN so someone can pay you is normal and generally low-risk. Still, avoid posting it publicly, and never share online banking passwords or one-time codes alongside it.