According to the ISO compliant IBAN Standard issued by the Central Bank of Bahrain (CBB) in February, 2011, all IBANs have a fixed length of 22 characters.
IBAN has two main components i.e. the header and the Basic Bank Account Number (BBAN).
The header helps to identify and verify the IBAN internationally. It contains the ISO two letter country code and the two check digits. Accordingly, the first 2 characters of an IBAN for Bahrain are always ‘BH’ (the ISO country code which identifies Bahrain, where the customer account resides). The third and the fourth characters of an IBAN are always the two check digits, generated by a bank in Bahrain, where the customer maintains his account.
The BBAN helps to identify an account number of a customer, as well as his bank, domestically. It comprises the Bank Identifier (which identifies the account holding bank) and the customer account number. In the case of Bahrain, the Bank Identifier is the first 4 letters of the SWIFT Code (BIC) of the respective account holding bank. The remaining part of the BBAN is the existing customer account number.
The length of the customer account number in the IBAN is fixed as 14 characters. It can contain numbers (0 to 9) and upper case letters (A to Z) depending on the respective bank. The length and structure of BBAN varies from country to country.