About this IBAN validator
An IBAN, the International Bank Account Number, identifies a bank account in a standard way so payments can cross borders. This IBAN validator checks the structure of an IBAN the same way banks' systems do first: it confirms the country is known, the length is right for that country, only letters and digits are used, and the two check digits pass the mod-97 test from ISO 13616. It also splits the number into its parts and writes it in groups of four characters. All checks run in your browser, and the number you type is not sent anywhere.
How an IBAN is built
An IBAN starts with a two-letter country code, then two check digits, then the Basic Bank Account Number (BBAN), whose layout is set by each country. For the sample GB82 WEST 1234 5698 7654 32, GB is the country, 82 the check digits, WEST the bank code, 123456 the sort code (branch) and 98765432 the account number. The total length depends on the country, from 15 characters in Norway to 33 or more in a few others, and this tool checks it against the registry lengths.
The mod-97 check
- Move the first four characters (country code and check digits) to the end.
- Replace each letter with a number, A as 10, B as 11, up to Z as 35.
- Treat the result as one very large number and divide by 97.
- If the remainder is 1, the IBAN passes.
The check catches any single wrong character and almost every swap of two neighbouring characters. If an IBAN fails but its length and characters are right, the tool shows the check digits that would make it pass, which helps when you spot a typo in the rest.
What a valid result does not mean
- It does not prove the account exists, is open, or belongs to the person you expect. Only the bank can confirm that.
- It does not check national check digits inside the account number for every country, nor the bank code against a bank list.
- The bank and account split is shown for common countries, including Germany, the United Kingdom, France, Spain, Italy and the Netherlands. For other countries the part after the check digits is shown as one block.
Never rely on a format check alone before sending a large payment. Confirm the details with the recipient by a second channel. For money maths, see the currency converter and the compound interest calculator, and to check a phone number use the phone number parser.
Frequently asked questions
Enter it in the box. The tool removes spaces, checks the country code and length, and runs the mod-97 test. A green result means the structure and check digits are correct.
No. It only means the number is correctly formed. The account may be closed or belong to someone else, and only the bank can confirm that.
The length depends on the country. Norway uses 15 characters, Germany 22, the United Kingdom 22, France 27 and Malta 31. The tool checks the length for each country.
The first two letters are the country code and the next two digits are check digits calculated from the rest of the number, so that mistakes can be detected.
One character is probably wrong or two are swapped. If the length is correct, the tool shows the check digits that would pass so you can compare them with what you were given.
No. All checks run in your browser. Nothing you type is uploaded or stored.