What is IBAN?
IBAN (International Bank Account Number) is an internationally agreed system of identifying bank accounts across national borders. It consists of up to 34 alphanumeric characters: 2-letter country code, 2 check digits, and country-specific Basic Bank Account Number (BBAN).
How IBAN Validation Works
Our validator uses the mod-97 algorithm according to ISO 13616 standard.
- Check format and length
- Rearrange the IBAN by moving the first 4 characters to the end
- Convert letters to numbers (A=10, B=11, ..., Z=35)
- Calculate modulo 97 of the resulting number
- IBAN is valid if the remainder equals 1
References: ISO 13616, mod-97 algorithm
IBAN Structure
Country Code
2-letter ISO 3166-1 alpha-2 code
Check Digits
2 digits calculated using mod-97
BBAN
Basic Bank Account Number (country-specific format)
Supported Countries
Our validator supports IBAN formats from 80+ countries including all EU member states, SEPA countries, and many others worldwide. Each country has a specific IBAN length and structure that we validate according to ISO 13616 standard.
Common Use Cases
- Verify IBAN before making international wire transfers
- Check IBAN format when setting up payment systems
- Validate customer bank account numbers in e-commerce
- Double-check IBAN accuracy to avoid payment errors