Postcodes in Australia

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Postcodes in Australia

Postcodes are four-digit numbers used to sort and send mail more efficiently. They appear at the end of an address, after the town or suburb and state, and before the country. For example:
Recipient name
100 Citizen Road
BLACKTOWN NSW 2148

History and who runs them
Postcodes were introduced in 1967 by the Postmaster-General’s Department. Today, Australia Post manages them. They are published in booklets and online for people to use.

How they help sorting mail
Many Australian envelopes have four orange boxes in the bottom right corner. Writing the postcode in those boxes helps automatic sorting machines read the address. A “postcode square” was added in 1990 so machines can read postcodes even faster.

Two postcodes for one place
Some places have two postcodes—one for street delivery and another for PO Boxes. Very large mail recipients, like hospitals or universities, once had their own postcodes (large volume receivers, or LVRs). The LVR program has been winding down since 2006.

How postcodes are organized
- The first digit usually shows the state or territory.
- The second digit helps identify a region within that state.
- The last two digits divide the area into smaller delivery zones.

Postcodes can be simple or quite complex
A single postcode can cover many towns, or a single town can have several postcodes. In rural areas, one postcode might cover a large area with only a few people. In cities, there are many different postcodes.

Cross-border and unusual cases
Some postcodes cross state borders, and a few small places don’t have a postcode. External territories are included in Australia Post’s system. For example, some border towns share the same postcode on either side of a state line.

Beyond mail
Postcodes are also used for maps, statistics, planning, insurance pricing, and even bus stop numbers. They help government agencies and businesses understand where people live and work.

Sorting and technology
To speed up sorting, Australia Post uses barcodes and other sorting numbers on letters. This helps place mail in delivery order and makes processing faster.