IBAN Validator
Validate IBAN numbers instantly with MOD-97 checksum verification. See country code, check digits, and BBAN breakdown. Free, 100% in your browser.
Reference
What is an IBAN?
An IBAN (International Bank Account Number) is a standardized format for identifying bank accounts across national borders, defined by ISO 13616. It consists of a 2-letter country code, 2 check digits, and a country-specific BBAN (Basic Bank Account Number). IBANs are used in over 80 countries, primarily in Europe, the Middle East, and parts of Africa and the Caribbean. They reduce errors in international transfers by providing a machine-readable, self-validating account format.
How IBAN validation works (MOD-97)
IBAN validation uses the MOD-97 algorithm defined in ISO 7064:
1. Move the first 4 characters (country code + check digits) to the end.
2. Replace each letter with two digits (A=10, B=11, …, Z=35).
3. Compute the remainder when dividing the resulting large number by 97.
4. If the remainder is 1, the IBAN is valid. This catches all single-character errors and over 99% of transposition errors.
IBAN by country
Each country defines its own IBAN length: Germany (DE): 22 characters. France (FR): 27. Spain (ES): 24. United Kingdom (GB): 22. Italy (IT): 27. Netherlands (NL): 18. Switzerland (CH): 21. Portugal (PT): 25. Belgium (BE): 16. Austria (AT): 20. The United States, Canada, Australia, and New Zealand do not use IBAN — they use domestic routing/account number systems.
Privacy
All validation runs 100% in your browser using the MOD-97 algorithm. No data is sent to any server — your bank details never leave your device.