BSB Lookup
Find which Australian bank a BSB belongs to and check its format
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A BSB has no check digit
Almost every identifier has arithmetic built into it: an ABN divides by 89, an IBAN by 97, a Medicare number carries a weighted check digit. A Bank State Branch number has none of that. Six digits, no relationship between them, no way to tell a real one from a made-up one by calculation alone.
What can be checked is allocation. The first two or three digits identify the institution, and Australian Payments Network publishes which prefix belongs to whom. This tool resolves that prefix, so you can tell that 062-000 is Commonwealth Bank and 083-004 is NAB without looking anything up. What it will never do is call a well formed six digit number invalid, because there is no basis for that claim.
What the prefix tells you
Enough for most questions. "Which bank is this BSB?" is answered by the prefix alone, and answered offline, since the whole institution table is a few kilobytes bundled into this page. The remaining digits identify a specific branch, and branch names and addresses live in the full AusPayNet directory, which is a much larger file and a separate question of redistribution rights. If you need the branch, AusPayNet publishes its own lookup.
Prefixes move
Banks merge, are acquired and hand their prefixes on, and the directory is republished monthly. A prefix this tool does not recognise may be newly allocated, and one it does recognise may have changed hands since our snapshot. The date of the copy in use is shown with every result, which is the honest way to present data that ages.
Storing and formatting BSBs
Store six digits as text so that a leading zero survives, and display them as three digits, a dash and three digits. Accept input with or without the dash, since both are common on statements and invoices. A BSB alone is not enough to send money: it identifies a branch, and needs an account number alongside it. For the New Zealand equivalent, see the New Zealand bank account validator; for Europe, the IBAN validator.
Institution data derived from material published by Australian Payments Network.
Frequently Asked Questions
Does a BSB have a check digit?
No. A BSB is six digits with no arithmetic relationship between them, which means no calculation can tell a real BSB from an invented one. The only meaningful check is whether the prefix has been allocated to an institution, which is what this tool does.
How do I tell which bank a BSB belongs to?
The first two or three digits are the institution prefix: 01 is ANZ, 03 and 73 are Westpac, 06 and 062 are Commonwealth Bank, 08 is NAB. This tool resolves the prefix against the list Australian Payments Network publishes, so you get the institution without a lookup.
Why does this tool not show the branch name and address?
Branch detail lives in the full AusPayNet BSB directory, a much larger file with its own terms of use. The institution list is a small factual extract that answers the common question offline. For a specific branch, AusPayNet publishes its own lookup.
My BSB is not recognised. Is it fake?
Not necessarily. The directory is republished monthly, prefixes are reassigned when institutions merge, and our copy is a snapshot dated on the results. An unrecognised prefix means it is not in that snapshot, which is a different statement from the number being invalid.