Bank State Branch

A Bank State Branch (often referred to as "BSB") is the name used in Australia for a bank code, which is a branch identifier. The BSB is normally used in association with the account number system used by each financial institution. The structure of the BSB + account number does not permit for account numbers to be transferable between financial institutions. While similar in structure, the New Zealand and Australian systems are only used in domestic transactions and are incompatible with each other. For international transfers, a SWIFT code is used in addition to the BSB and account number.

The BSB identifier consists of six numerals, the first two or three of which is a bank identifier. The BSB identifier is used for processing of paper and electronic transactions, but not in payment card numbering.

In Australia, the Australian Payments Clearing Association (APCA) is now the regulatory body of cheque clearances and of the BSB codes in Australia. APCA assigns the bank code to a financial institution and the financial institution allocates the other digits to its branches, in line with guidelines set by APCA. Some financial institutions have more than one bank identifier, arising from mergers of financial institutions or consolidating by banks of their trading and savings banks operations. As of March 2012, almost 14,300 unique BSB code values were in use.

In Australia, BSB codes are allocated by the Australian Payments Clearing Association (APCA). BSB codes are used in a number of payment systems in Australia. To access the various clearance systems a financial institution must have its own BSB or use an intermediary with a BSB.

Cheques are the least used form of non-cash payment in Australia, but the most by value. Financial institutions are required to include BSB and bank account numbers on cheques, at the bottom of the cheque in MICR form, which identify the specific bank account number to be debited. BSB codes are also used on deposit and other vouchers. Paper transactions are processed under the Australian Paper Clearing System (APCS) (also known as CS1) drawn up by APCA. Account instructions which do not have a BSB code must be processed manually.

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