Find Your Postcode in Australia

An Australian postcode is four digits, and the first of them tells you roughly which state you are in. Press the button and your position becomes the postcode covering that spot, with the suburb and state so you can check it looks right.

Your location is only used to find your postcode.

Postcode

2000

Australia

Example

The Postcode Format

Format

Four digits (2000)

Example

2000

An Australian postcode is four digits and nothing else. There is no space, no letter and no extension, which makes it one of the simplest postal code formats in use anywhere.

The simplicity hides one trap. Leading zeros are real: the Northern Territory uses codes beginning 08, and Darwin is 0800. Stored as a number rather than as text, 0800 becomes 800 and stops being a valid postcode. This is the single most common way an Australian address is corrupted in a database, and it is entirely avoidable by keeping postcodes as text.

A postcode on its own is not an address. Australia Post expects the suburb, the state abbreviation and the postcode together on the final line — SYDNEY NSW 2000 — because suburb names repeat across states and the postcode resolves which one is meant.

What Each Part of a Postcode Means

Read left to right, each part of a Australia postcode narrows the destination down.

Breakdown of each part of a Australia postcode
Part	Identifies	What it means
Digit 1	State or territory	A broad state band: 2 for New South Wales, 3 for Victoria, 4 for Queensland, 5 for South Australia, 6 for Western Australia, 7 for Tasmania, and 0 for the Northern Territory.
Digits 1-2	Region within the state	Narrows to a region — a capital city, or a part of the state beyond it.
Digits 3-4	Delivery area	The particular suburb, town or delivery area within that region.
The 1000s	Post office boxes	Codes beginning with 1 are New South Wales boxes and large-volume receivers rather than ordinary suburbs, which is why they do not fit the state pattern.
The 8000s and 9000s	Large-volume receivers	Reserved blocks for Victoria and Queensland respectively, used for organisations that receive enough mail to need their own code.

How postcodes work in Australia

Australia introduced four-digit postcodes in 1967, and the first digit was not chosen arbitrarily. It was taken from the radio call-sign prefixes already in use for each state, which is why New South Wales is 2, Victoria 3, Queensland 4, South Australia 5, Western Australia 6 and Tasmania 7. An existing, familiar numbering was reused rather than invented from scratch.

From that starting point the code narrows in the ordinary way. The first two digits pick out a region within the state — a capital city, or a stretch of country beyond it — and the last two name the suburb or town. Because the country is so unevenly populated, a single code can cover a few city blocks in Sydney or a vast area of inland Western Australia, and both are working as intended.

Two groups of codes do not follow the state logic at all. Blocks beginning with 1, 8 and 9 are reserved for post office boxes and for large-volume receivers: organisations such as government departments, banks and universities that take enough mail to warrant a code of their own. A code in one of those ranges names a recipient rather than a patch of ground, so treating it as geography produces nonsense.

The state rule also fails at a handful of borders. Postcodes follow how mail actually moves, and where a town is most easily served from across a state line it takes the code that matches the delivery, not the one that matches the map. These cases are rare but they are real, and software that infers a state purely from the first digit will get them wrong.

Codes change as the country grows. New suburbs are allocated codes, and delivery areas are reorganised, so a postcode is correct for an address at a point in time rather than permanently.

Suburb, state and postcode travel together

Australian addressing treats the last line as a unit: suburb, state abbreviation, postcode, all in capitals. SYDNEY NSW 2000. There is a reason the three are always written together and it is not convention for its own sake.

Suburb names repeat. There is more than one Richmond, more than one Springfield and more than one Newtown, in different states. The suburb name alone does not identify a place, and the postcode is what resolves the ambiguity. Equally, a postcode on its own can cover several suburbs, so it does not identify the suburb either. Together they do.

This is why a form that asks only for a postcode and then guesses the suburb will sometimes guess wrong, and why it is worth checking what it filled in rather than assuming it knew.

Leading zeros and the Northern Territory

Codes in the Northern Territory begin with 0, and that zero causes more trouble than any other feature of the format.

Darwin is 0800. Stored in a numeric column, a spreadsheet cell formatted as a number, or a JSON field that a parser helpfully converts, it becomes 800 — which is not a valid Australian postcode at all. The address looks fine to whoever typed it and is broken by the time it reaches the carrier.

The fix is always the same and always worth repeating: a postcode is a string of characters that happen to be digits, not a quantity. Nothing is ever added to a postcode or sorted numerically for a good reason, so there is no benefit to storing it as a number and one very common failure mode if you do.

Where a lookup and Australia Post can disagree

This tool answers which postcode covers the point your device reported. Australia Post answers which postcode belongs to a given address. Usually those agree.

When they do not, the usual cause is the accuracy of the position itself, which falls off indoors, among tall buildings and when your device is working from Wi-Fi and mobile signals rather than a clear sky. Near the edge of a delivery area that is enough to return the code next door.

The other cause is that delivery areas follow mail routes. A boundary can run down the middle of a street or around a block in a way the street layout does not suggest. For filling in a form or checking a code looks plausible, a lookup is fast and usually right. For anything consequential — a legal document, an insurance policy, a valuable parcel — confirm the address with Australia Post.

Frequently Asked Questions

Can I find a postcode from an address here?

No. This site works only from your current position: your device reports where it is, and that point becomes the postcode covering it. There is no address database behind it. To search from an address, use the Australia Post postcode search.

What does the first digit mean?

It identifies the state or territory — 2 New South Wales, 3 Victoria, 4 Queensland, 5 South Australia, 6 Western Australia, 7 Tasmania, 0 Northern Territory. Codes beginning 1, 8 and 9 are reserved for post office boxes and large-volume receivers instead.

Why is my postcode showing as three digits?

Because it has been stored as a number somewhere and the leading zero has been dropped. Northern Territory codes begin with 0, so 0800 becomes 800. Postcodes should always be stored as text.

Does one postcode mean one suburb?

Not necessarily. A postcode can cover several suburbs, and a large suburb can have more than one. That is why Australian addresses always write the suburb, state and postcode together on the last line.

Why does a form ask for a ZIP code?

Because it was built for US addresses. Your four-digit Australian postcode is the right answer. If the field insists on five digits it cannot handle an Australian address properly, and padding the value to fit will only produce a record that cannot be delivered against.

Do postcodes line up with council areas?

No. Postcodes were built around mail delivery, so they cross local government boundaries freely. Anything that needs a council area should be derived from the address rather than from the postcode.