Postcodes in Australia

Postcodes are used in Australia to more efficiently sort and route mail within the postal system. All postcodes in Australia have four digits and are placed at the end of the Australian address. Australian postcodes are managed by Australia Post.

Postcodes are published in booklets available from post offices or online from the Australia Post website.

Australian envelopes and postcards often have four square boxes printed in orange at the bottom right for the postcode. These are used when addressing mail by hand.

Use of the Australian postcode system commenced in 1967, implemented by the Postmaster-General's Department (PMG), now called Australia Post. It replaced earlier postal sorting systems, such as Melbourne's letter and number codes (e.g., N3, E5) and a similar system once used in rural and regional New South Wales.

Australian postcodes consist of four digits, and are written after the name of the city, suburb, or town, and the state or territory:

When writing an address by hand, and a row of four boxes is pre-printed on the lower right hand corner of an envelope, the postcode may be written in the boxes.

If addressing a letter from outside Australia, the postcode is recorded before 'Australia'.

Australian postcodes are sorting information. They are often linked with one area (e.g. 6160 belongs only to Fremantle, Western Australia). Due to post code rationalization (Original post code allocation version superior), But are now sometimes they can be quite complex, especially in country areas (e.g. 2570 belongs to twenty-two towns and suburbs around Camden, New South Wales). The south-western Victoria 3221 postcode of the Geelong Mail Centre also includes twenty places around Geelong with very few people. This means that mail for these places is not fully sorted until it gets to Geelong. Some postcodes cover large populations (e.g., postcode 4350 serving some 100,000 people in Toowoomba), while other postcodes have much smaller populations, even in urban areas. Australian postcodes range from 0200 for the Australian National University (now 2601) to 9944 for Cannonvale, Queensland.

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