What the Australia BSB Code Finder does
An Australian BSB is six digits written XXY-ZZZ: two digits for the institution, one for the state the branch was registered in, and three for the branch itself. This page splits a BSB into those three fields, names the institution from a short dated list where it can, decodes the state digit, and checks a whole pasted list at once.
It is deliberately modest about what it proves. A BSB has no check digit at all - unlike a US routing number or a UK account number, there is no arithmetic to run - so the only structural test possible is 'is it six digits'. Everything beyond that is a lookup, and AusPayNet publishes the authoritative BSB file that this page does not bundle.
The check runs in this browser tab and nothing is uploaded.
How to use it
- Paste a BSB with or without the dash. The three fields, the indicative institution and the state appear as you type.
- To check several, paste one per line and read the table.
- Open 'What the bundled list covers' to see exactly which prefixes are in the list and when it was reviewed - so an absent institution is obviously an absent listing rather than a verdict.
- Export as CSV or JSON for a payment-file review.
Reading the results
The first two digits are the institution. ANZ is 01, Westpac 03 and 73, Commonwealth Bank 06 and 76, NAB 08 and 78. A few institutions are identified by three digits instead - Bendigo and Adelaide Bank at 633, ING at 923 and 936 - which is why the page reports whether it matched on two digits or three.
The third digit is the state of registration: 2 for New South Wales and the ACT, 3 for Victoria, 4 for Queensland, 5 for South Australia and the Northern Territory, 6 for Western Australia, 7 for Tasmania, and 8 or 9 for intermediaries rather than a state. It tells you where the branch was registered, not where the account holder lives.
The last three digits are the branch, allocated by the institution under AusPayNet's guidelines. There is no open register mapping them to addresses.
An unlisted prefix means 'not in this list'. Australia has well over a hundred BSB-holding institutions, and credit unions and building societies make up most of them.
Worked example: reading 062-000 and 013-303
062-000 splits into 06 (Commonwealth Bank of Australia), 2 (New South Wales and the ACT) and 000 (the branch field). It is one of CBA's widely quoted head-office BSBs, which is why a payment form often pre-fills something like it.
013-303 splits into 01 (ANZ), 3 (Victoria) and 303. Same length, entirely different institution and state - which is the point of reading the fields rather than treating the six digits as one opaque number.
Now try 992-000. It is six digits, so the format check passes, but 99 is not in the bundled list, so the page says 'not listed here' rather than inventing a bank. That is the honest answer: without a check digit there is no arithmetic that could distinguish an unallocated prefix from one the list simply does not carry.
Why there is nothing to validate
Schemes that carry a check digit - the ABA routing number, a Canadian cheque's MICR line in some layouts, the UK's modulus rules, IBAN's mod-97 - were designed when numbers were transcribed by hand and a typing error had to be caught before it became a misdirected payment. The BSB was not given one, and Australian account numbers are not standardised in length either, so there is no arithmetic relationship between a BSB and an account number to test.
In practice that means a mistyped Australian BSB and account number is caught by the receiving institution rejecting the payment, or by PayID's name confirmation, rather than by anything a form can check before submitting. It is a good argument for using PayID where one exists.
BSB, PayID and the Osko rails
A BSB and account number address an account through the traditional clearing rails. A PayID - a phone number, email address or ABN registered against an account - addresses the same account through the New Payments Platform, and crucially returns the registered account name before you confirm the payment.
That name check is the thing a BSB cannot give you. If you are paying somebody new and a PayID is offered, it is the safer route for exactly the reason this page keeps repeating: format checking tells you about a string, and only the receiving institution can tell you about an account.
Limitations: what the result does not prove
- A BSB has no check digit, so this page checks the format and looks the prefix up. It cannot tell you that a BSB is currently allocated, which branch it is, or that an account behind it exists.
- The institution list is short, dated and indicative. AusPayNet's BSB file is the authority, and most Australian BSB holders - credit unions, building societies, smaller mutuals - are not in the bundled list at all.
- The state digit records where the branch was registered. Accounts are portable, so it says nothing about where the customer is.
- It cannot confirm account ownership, an available balance, or that a payment will succeed.
Privacy: where your data goes
Everything you paste, type or drop is processed in this browser tab. It is not uploaded, logged, stored or sent to analytics. Session recording and tag-manager scripts are switched off on this page.
Standards and sources
- AusPayNet - BSB numbers - checked 19 Sep 2026
- AusPayNet - Australian Payments Network
- New Payments Platform Australia - PayID
- Reserve Bank of Australia - the Australian payments system
Frequently asked questions
What does a BSB number mean?
Bank-State-Branch. The first two digits identify the financial institution, the third the state the branch was registered in, and the last three the branch itself. AusPayNet allocates the institution codes and each institution allocates its own branch numbers under their guidelines.
Does a BSB have a check digit?
No. There is no arithmetic that can validate a BSB, and none that links a BSB to an account number. The only structural check possible is that it is six digits, which is why this page is careful to call its institution lookup indicative rather than a verdict.
What does the third digit of a BSB mean?
The state of registration: 2 for New South Wales and the ACT, 3 for Victoria, 4 for Queensland, 5 for South Australia and the Northern Territory, 6 for Western Australia, 7 for Tasmania. An 8 or 9 marks an intermediary rather than a state, and 0 or 1 vary by institution.
Why does my credit union's BSB not show an institution name?
Because the bundled list holds only the larger institutions, and most of Australia's BSB holders are credit unions, mutuals and building societies. An absent name means the list does not carry that prefix - it says nothing about whether the BSB is valid.
Can I find a branch address from a BSB?
Not from the number. Branch codes are allocated by each institution and there is no open register mapping them to addresses, so branch lookups you find elsewhere are scraped from bank websites and go stale as branches close.
Why do some banks have several BSB prefixes?
Mergers and acquisitions, mostly. Westpac carries 03 and 73, Commonwealth Bank 06 and 76, NAB 08 and 78, and St George appears under both 11 and 33 after joining Westpac. The old ranges keep working because customers' account details were never reissued.
Is a BSB the same as a sort code or a routing number?
It fills the same role - identifying an institution and branch inside one country's clearing system - but the formats and the checks differ. A UK sort code is six digits with a modulus rule over the account number; a US routing number is nine digits with a weighted checksum; a BSB is six digits with nothing.
What should I check before paying a new Australian payee?
Use a PayID if the payee has one, because the New Payments Platform shows you the registered account name before you confirm. Otherwise confirm the BSB and account number with the payee through a channel you already trust - not from the invoice you are paying.
Last reviewed by the A2Z.Tools team against the sources listed above.
