Understanding IBAN Structure
Every IBAN follows the same overall structure, but the internal BBAN (Basic Bank Account Number) portion varies significantly by country. Understanding your country's IBAN format helps you verify account numbers manually and spot errors before making transfers.
IBAN Length by Region
IBAN lengths range from 15 characters (Norway) to 34 characters (Malta). European SEPA country IBANs tend to be between 18 and 27 characters. Middle Eastern IBANs are generally longer, often 23–30 characters. The length is fixed per country — any IBAN that's the wrong length for its country code is automatically invalid.
What is the BBAN?
The BBAN (Basic Bank Account Number) is the country-specific portion of an IBAN — everything after the 4-character header (country code + check digits). It typically contains the bank code, branch code, and account number in a format defined by the national banking authority. The BBAN format is standardised by the European Committee for Banking Standards (ECBS).
How to Read an IBAN
Take the German IBAN DE89 3704 0044 0532 0130 00:
- DE — Country: Germany
- 89 — Check digits
- 37040044 — Bank code (BLZ): Commerzbank Frankfurt
- 0532013000 — Account number
Our IBAN validator does this decomposition automatically for any IBAN you enter.