IBAN Length Validator

Understanding the IBAN across countries

An IBAN (International Bank Account Number, standard ISO 13616) is a single, internationally agreed way to identify a bank account. Every IBAN starts with a 2-letter country code, then 2 check digits, then a country-specific BBAN (Basic Bank Account Number). It is always stored without spaces and only printed in groups of four for readability.

Originally created for SEPA (Single Euro Payments Area) in Europe, the IBAN has since been adopted by many countries beyond the EU.

Length depends on the country

The country prefix determines a fixed total length. A few examples:

• Norway (NO) — 15 characters.
• Germany (DE) — 22 characters.
• Brazil (BR) — 29 characters.
• Malta (MT) and others — up to 34 characters.

The IBAN registry, maintained by SWIFT, defines the exact BBAN layout and length for each participating country.

The Brazilian IBAN

Brazil's IBAN starts with BR and is 29 characters long. Its BBAN is: bank code (8 digits) + branch code (5 digits) + account number (10 digits) + account type (1 character) + owner type (1 character).

The universal mod-97 check

Whatever the country, validation uses the same mod-97 algorithm (ISO 7064, MOD 97-10): move the first 4 characters to the end, replace each letter with two digits (A=10 … Z=35), read the result as one big integer, and confirm that integer mod 97 equals 1.

Common pitfalls

• Assuming every IBAN has the same length — it is fixed per country, not universal.
• Counting spaces in the length: validate the IBAN without spaces.
• Forgetting that the country prefix must match the expected length and BBAN layout.
• Assuming a valid checksum means the account exists: mod-97 only proves structure and check digits.

FAQ

Is the IBAN length the same everywhere? No. It is fixed per country, ranging from 15 (Norway) up to 34 characters.

Is IBAN used outside Europe? Yes. It is mandatory for SEPA but has been adopted by many countries beyond the EU, including Brazil.

Does a valid IBAN guarantee the account is real? No. Validation confirms the format and checksum only.