Australia
How to Find an Australian Postcode
Find the right Australian postcode from a suburb or street address, check it against the state, and know what to do when a suburb has several.
Updated 14 October 2026 · 3 min read
The most reliable way to find an Australian postcode is to use the lookup tools provided by Australia Post, the national postal operator. Searching by suburb gives you the postcode for most places, and searching by full street address resolves the cases where a suburb is split.
Start with the suburb and state
Postcodes are tied to localities. Give the suburb name together with the state or territory, because the same suburb name can appear in more than one state. A lookup by suburb returns the matching postcode or postcodes, and this answers the question for the majority of homes and businesses.
Use the full address when the suburb is split
Some suburbs are served by more than one postcode, for example where a locality is large or where part of it is served from a different post office. In those cases, a suburb-only search is not enough. Enter the street name and number so the lookup can assign the right delivery area. Australia Post's address search tools are designed for this, and they are the best source for a definitive answer.
Verify the result
Once you have a postcode, run through a quick check:
- Does the first digit fit the state? A code starting with 3 for a Queensland address is a red flag. See the postcode format guide for the ranges.
- Is the code four digits, with a leading zero if needed?
- Does the postcode match the printed postcode on a recent letter, bill or parcel label from the same address?
- Does the suburb name match the postcode in the lookup, not just a neighbouring suburb?
What to do if you are unsure
Ask the recipient. A recent piece of mail or an invoice has the exact line used for delivery. If the recipient is a business, the website's contact page often carries a correct address. For online shops, do not guess: an incorrect postcode can cause a parcel to be routed to the wrong area or the order to be flagged at checkout.
If the address is on a large property, an industrial estate or a remote road, the postcode only brings the parcel to the correct area. A UPCS code (prefix AU) can be shared with the courier to mark the exact entrance or loading dock. It is not a postcode and has no role in the Australia Post lookup; it only works as an additional location reference. See delivery and addressing in Australia for more detail.
A note on PO Box postcodes
Post office boxes often have their own postcodes, which can differ from the street postcode of the same town. Use the box postcode only for the PO Box line, and the street postcode for the physical address. To see how to write each one, read how to write an Australian address. The Australia overview summarises the whole system.
Frequently asked questions
Who maintains Australian postcodes?
Australia Post, the national postal operator, maintains the postcode system and provides its own lookup tools.
What if a suburb has more than one postcode?
Use the street address in the lookup rather than just the suburb name. If the lookup still returns several results, confirm with the sender or the property's own mail.