TL;DR Summary: A BSB (Bank State Branch) number is a 6-digit code used to identify a specific bank branch in Australia for domestic payment routing. Commonwealth Bank (CommBank) has over 4,390 BSB numbers allocated across its branch network, all beginning with the digits 06. You need a BSB number when making domestic Australian bank transfers, setting up direct debits, and receiving international wire transfers. For international inbound transfers, the BSB is used alongside the account number and CommBank's SWIFT code CTBAAU2S. Always verify your specific branch BSB before initiating any payment, as using the wrong code can delay or misdirect a transfer.
Introduction: What Is a BSB Number in Australia
The BSB, an acronym for Bank State Branch, is a six-digit identification code used in Australia's domestic payment clearing systems to identify the specific branch at which a bank account is held. The BSB number is a fundamental element of the Australian Paper Clearing System (APCS) and the Bulk Electronic Clearing System (BECS), the two primary mechanisms through which retail and institutional payments are processed between Australian financial institutions. Without a valid BSB, a domestic Australian bank transfer cannot be routed to its intended destination.
Every Australian bank, credit union, and building society that participates in the domestic clearing system is allocated one or more BSB numbers. For large banks such as Commonwealth Bank, which operates an extensive branch network across all Australian states and territories, thousands of individual BSB numbers are active simultaneously, each tied to a specific branch location.
How BSB Numbers Are Structured
A BSB number is always exactly six digits in length, conventionally written in the format XXX-XXX with a hyphen after the third digit. The six digits encode three distinct layers of information. The first two digits identify the financial institution itself, the bank or institution code. The third digit identifies the state or territory in which the branch is located, using a standardized numeric state code where 2 represents New South Wales and the Australian Capital Territory, 3 represents Victoria, 4 represents Queensland, 5 represents South Australia and the Northern Territory, 6 represents Western Australia, and 7 represents Tasmania. The final three digits identify the specific branch within that state.
For example, in the BSB number 062-000, the first two digits 06 identify Commonwealth Bank, the third digit 2 identifies New South Wales, and the last three digits 000 identify the specific branch location. This structured encoding means that any BSB number reveals at a glance both the institution and the state associated with the branch holding the account.
Commonwealth Bank BSB Numbers
Commonwealth Bank of Australia uses 06 as its institution identifier, meaning all CommBank BSB numbers begin with 06. With over 4,390 BSB numbers allocated across its branch network, CommBank has one of the most extensive BSB footprints of any Australian bank, reflecting its status as the country's largest bank by retail deposits and branch network size. The allocated codes include branches across all six states and the two mainland territories, from major metropolitan branches in Sydney, Melbourne, Brisbane, and Perth to regional and rural branches across Australia.
Unlike some smaller financial institutions that operate with a single centralised BSB for all accounts regardless of branch, CommBank assigns individual BSB numbers to each branch location. This means that a CommBank customer who opened their account at a Sydney City branch has a different BSB to a CommBank customer who opened their account at a Melbourne Docklands branch, even though both accounts are held at the same institution. The branch of account opening determines the BSB, not the current residential location of the account holder.
When You Need a CommBank BSB Number
A CommBank BSB number is required in several common financial scenarios. For domestic Australian bank-to-bank transfers, the sender must provide both the recipient's BSB and account number to route the payment to the correct CommBank branch account. This applies to one-off transfers initiated through internet banking or a mobile app, as well as to recurring payments and direct debits. When setting up payroll direct deposit, a Commonwealth Bank account holder must provide their employer with both their BSB and account number for the payroll instruction to be correctly directed.
A BSB is also required for BPAY payments in some configurations, for setting up periodic payment instructions, and for receiving funds from another Australian bank. Cheques printed on CommBank accounts include the BSB and account number in MICR format at the bottom of the cheque, allowing automated processing in the paper clearing system. The New Payments Platform (NPP), which enables real-time bank-to-bank payments in Australia via PayID or BSB and account number, also uses the BSB when account-based routing is selected rather than a PayID identifier.
How to Find Your CommBank BSB Number
The most reliable source for a CommBank BSB number is the account holder's own banking records. CommBank account statements, whether received by mail or accessed digitally through NetBank or the CommBank mobile app, display the BSB and account number prominently near the top of each statement. Within NetBank, the BSB can be found by navigating to the account details view for the relevant account. The CommBank mobile app displays it under the account information section accessible from the account summary screen.
Account holders who are unsure of their BSB can contact CommBank customer service by calling 13 2221 during business hours. A customer service representative can confirm the BSB for any account after verifying the caller's identity. CommBank's online branch locator can also be used to identify the BSB for a specific branch address, and the AusPayNet BSB lookup tool at bsb.auspaynet.com.au is the authoritative public source for verifying any Australian BSB number.
Using a BSB for International Transfers to CommBank
When receiving an international wire transfer from outside Australia into a Commonwealth Bank account, the BSB number is required alongside additional information. International senders must provide CommBank's SWIFT code CTBAAU2S, the recipient's full name, the recipient's CommBank BSB number, and the account number. For transfers from countries that use IBAN numbers, the sender's bank may also require confirmation that Australian banks do not use IBAN and that the BSB plus account number serves the equivalent routing function within Australia's domestic clearing system.
It is important to note that international SWIFT transfers to Australian bank accounts typically deliver a lower effective value than the mid-market rate would suggest, because the sending bank applies an exchange rate margin and may route the payment through correspondent banks that charge intermediary fees. Senders using specialist digital transfer platforms that provide the recipient's CommBank account details alongside a local currency receiving account can materially reduce the total cost relative to a conventional bank SWIFT wire.
BSB vs SWIFT Code: Key Differences
The BSB and SWIFT code serve related but distinct purposes in the Australian banking context. A BSB is a domestic identifier used exclusively within Australia's national payment clearing systems. It identifies the specific branch of a specific Australian bank and is used for all domestic transfers, direct debits, and payroll instructions. A SWIFT code, by contrast, is an international identifier used to route cross-border payments through the SWIFT global messaging network. It identifies the institution at the national level without specifying a particular branch.
For a domestic transfer from one Australian bank to a CommBank account, only the BSB and account number are needed. For an international wire transfer from a foreign bank to a CommBank account, the SWIFT code is required at the institution level, with the BSB and account number then used to identify the specific account within CommBank's system. Both are needed simultaneously for inbound international wires to Australia.
Frequently Asked Questions
What does a Commonwealth Bank BSB number look like?
A CommBank BSB number is always six digits long, conventionally written in the format XXX-XXX. All CommBank BSB numbers begin with 06, which is the institution identifier for Commonwealth Bank. The third digit indicates the state (for example, 2 for NSW, 3 for Victoria, 4 for Queensland), and the final three digits identify the specific branch. An example CommBank BSB format would be 062-XXX for a NSW branch.
How do I find my Commonwealth Bank BSB number?
The easiest ways to find your CommBank BSB number are through NetBank online banking (under account details), the CommBank mobile app, or on your printed or digital bank statement. CommBank customer service on 13 2221 can also confirm your BSB after verifying your identity. Each account's BSB is tied to the branch where it was opened and does not change when you move address or state.
Do all Commonwealth Bank branches have the same BSB?
No. Commonwealth Bank assigns a unique BSB to each of its branch locations, with over 4,390 different BSB numbers allocated across the network. Each CommBank branch across Australia has its own specific code. Using the BSB of the wrong branch can cause a payment to be delayed or to arrive in the wrong account. Always use the BSB specific to the branch where the recipient's account was opened.
Can I use just the BSB to receive an international transfer?
No. For international wire transfers, the BSB alone is not sufficient. International senders require Commonwealth Bank's SWIFT code CTBAAU2S in addition to the recipient's BSB number and account number. Some sending banks also require the recipient's full name and the bank's address. The SWIFT code routes the payment to Commonwealth Bank at the international level, while the BSB and account number identify the specific account within the bank's domestic system.
What happens if I give the wrong BSB for a CommBank transfer?
Using an incorrect BSB can cause a payment to be directed to the wrong branch or to fail entirely if the BSB does not correspond to a valid CommBank account at that branch. If the BSB and account number together match an existing account at the wrong branch, the funds may be credited to that unintended account. Recovering misdirected funds requires a formal trace request with both the sending and receiving bank and can take several business days. Always verify the recipient's BSB directly with them before initiating any payment.
