The International Bank Account Number (IBAN) is a standardized format for identifying bank accounts across borders. Used in over 80 countries, every IBAN includes built-in check digits that catch 99%+ of transcription errors. A single wrong digit in an international wire transfer can send money to the wrong account — or nowhere at all. This IBAN Validator instantly checks any IBAN's format, length, and check digits, and uses the free OpenIBAN API to identify the associated bank name and BIC/SWIFT code.
How to Use the IBAN Validator
Validating an IBAN takes one step:
Enter the IBAN. Paste or type the full IBAN (with or without spaces). The validator accepts formats like 'GB29 NWBK 6016 1331 9268 19' or 'GB29NWBK60161331926819'.
The tool checks three things:
- Country code: Valid 2-letter ISO country code
- Length: Correct number of characters for that country (varies by country — UK is 22, Germany is 22, France is 27)
- Check digits: MOD-97 validation ensures no transcription errors
If the IBAN passes all checks, the tool queries OpenIBAN for the bank name and BIC code.
How IBAN Check Digits Work
The IBAN check digit algorithm (ISO 7064 MOD 97-10) works as follows:
- Move the first 4 characters (country code + check digits) to the end
- Replace each letter with its numeric value (A=10, B=11, ..., Z=35)
- Calculate the remainder when dividing this large number by 97
- If the remainder equals 1, the IBAN is valid
This algorithm catches all single-character errors and over 99% of transposition errors — making it one of the most reliable check digit systems in use.
IBAN Formats by Country
IBAN length and structure vary by country:
- Germany (DE): 22 characters — DE + 2 check digits + 8-digit bank code + 10-digit account
- United Kingdom (GB): 22 characters — GB + 2 check digits + 4-char bank + 6-digit sort code + 8-digit account
- France (FR): 27 characters — FR + 2 check digits + 5-digit bank + 5-digit branch + 11-char account + 2 national check digits
- Netherlands (NL): 18 characters — shortest IBAN format
- Malta (MT): 31 characters — longest common IBAN format
Step-by-Step Instructions
- 1Enter or paste an IBAN number (spaces are automatically removed).
- 2The tool validates the country code, length, and MOD-97 check digits.
- 3View the structured breakdown: country, check digits, bank code, account number.
- 4If valid, the tool queries the OpenIBAN API for bank name and BIC/SWIFT code.
- 5Use Batch Mode to validate multiple IBANs at once.