About BSB 303-256

303-256 is a BSB number of Bankwest (a division of Commonwealth Bank of Australia), assigned by the Australian Payments Clearing Association (APCA) for routing domestic bank transfers within Australia.

BSB Code Format

A BSB code consists of 6 digits. The first two digits identify the banking institution, and the remaining four identify the specific branch.

Some large financial institutions may have two BSB codes per branch — one for trading/cheque accounts and one for savings accounts. The first digit differentiates account types (e.g., 0 for trading, 7 for savings), while the second digit is shared.

How BSB Numbers Are Used

APCA assigns BSB codes to Australian banking institutions. These codes are required for various payment transactions. A banking institution needs its own BSB code (or an intermediary code) to access cheque clearance systems.

Paper Transactions

While cheques are the least common non-cash payment method in Australia, they carry significant value. Both the BSB and bank account numbers must appear in MICR format to identify the target account. The APCS (CS1) system handles paper transactions under the APCA framework.

Electronic Transactions

Electronic Fund Transfers (EFT) are the most popular non-cash payment method in Australia. Inter-bank EFT transactions use the Direct Entry system, which requires BSB and account numbers for debiting and crediting. The Bulk Electronic Clearing System (BECS), managed by APCA, processes these transactions.

International Transactions

Incoming international transfers require SWIFT codes alongside the BBAN (Basic Bank Account Number). Australia does not currently use IBAN codes for international transfers, as adopting them would require significant changes to banking databases and systems.