Postcodes in Australia are used to more efficiently sort and route mail in the Australian postal system. Postcodes in Australia have four digits and are placed at the end of the Australian address, before the country. Postcodes were introduced in Australia in 1967 by the Postmaster-General's Department and are now managed by Australia Post, Australia's national postal service. Postcodes are published in booklets available from post offices or online from the Australia Post website.
Australian envelopes and postcards often have four boxes printed in orange at the bottom right for the postcode. These are used to assist with the automated sorting of mail that has been addressed by hand for Australian delivery.
History Postcodes were introduced in Australia in 1967 by the Postmaster-General's Department (PMG) to replace earlier postal sorting systems, such as Melbourne's letter and number codes (e.g., N3, E5) and a similar system then used in rural and regional New South Wales. The introduction of the postcodes coincided with the introduction of a large-scale mechanical mail sorting system in Australia, starting with the Redfern Mail Exchange in Sydney.
The initial digit of each postcode was copied directly from the previously-existing numerical prefixes of Australian radio call signs, which were based on state/territory borders. Over time, however, the initial digits of postcodes have deviated from the radio system, for example, the 8000 series refers to special addresses in Victoria. It is sometimes stated, incorrectly, that the initial digits of the postcodes corresponded to the geographical boundaries of the official Australian Military Districts, that existed in 1911–1997. In fact, only the boundaries of the initial 2- and initial 3– postcodes were ever similar to the former 2nd and former 3rd Military Districts, respectively.
By 1968, 75% of mail was using postcodes, and in the same year post office preferred-size envelopes were introduced, which came to be referred to as "standard envelopes".
Postcode squares were introduced in June 1990 to enable Australia Post to use optical character recognition (OCR) software in its mail sorting machines to automatically and more quickly sort mail by postcodes.
Format Australian postcodes consist of four digits, and are written after the name of the suburb, or town, and the state or territory:
Recipient Name 100 Citizen Road BLACKTOWN NSW 2148
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 instead. When posting to an organisation, business names can be written instead of a recipient name. If an article is intended for a specific identity within an organisation, their identity can be prepended on the line above the business name, with c/- prepended to the business name.
If addressing a letter from outside Australia, the postcode is recorded before 'Australia', which is placed on a fourth line.
Geography Australian postcodes are sorting information. They are often linked with one area; e.g. 6160 belongs only to Fremantle, Western Australia. Due to postcode rationalisation, 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 and the surrounding area), 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.
Some towns and suburbs have two postcodes—one for street deliveries and another for post office boxes. For example, a street address in the Sydney suburb of Parramatta would be written like this:
Mr John Smith 99 George Street PARRAMATTA NSW 2150
But mail sent to a PO Box in Parramatta would be addressed:
Mr John Smith PO Box 99 PARRAMATTA NSW 2124
Many large businesses, government departments and other institutions receiving high volumes of mail had their own postcode as a Large Volume Receiver (LVR), e.g. the Royal Brisbane and Women's Hospital has the postcode 4029, the Australian National University had the postcode 0200. More postcode ranges were made available for LVRs in the 1990s. Australia Post has been progressively discontinuing the LVR programme since 2006.
Places without postcodes Some places in Australia do not have postcodes. These are typically remote areas with little or no population.
Allocation
Australian states and territories The first one or two numerals usually show the state or territory that the postcode belongs to
State/TerritoryAbbreviationPostcode rangeNew South WalesNSW1000—1999 (LVRs and PO Boxes only)2000—25992619—28992921—2999Australian Capital Territory ACT0200—0299 (LVRs and PO Boxes only)2600—26182900—2920Victoria VIC3000—39968000—8999 (LVRs and PO Boxes only)QueenslandQLD4000—49999000—9999 (LVRs and PO Boxes only)South AustraliaSA5000—57995800—5999 (LVRs and PO Boxes only)Western AustraliaWA6000—67976800—6999 (LVRs and PO Boxes only)TasmaniaTAS7000—77997800—7999 (LVRs and PO Boxes only)Northern TerritoryNT0800—08990900—0999 (LVRs and PO Boxes only)
Sometimes near the state and territory borders, Australia Post finds it easier to send mail through a nearby post office that is across the border:
PostcodeLocalityState derived fromPostcode rangesActual Statefor this locality 4825ALPURRURULAMQLDNT 0872ERNABELLANTSA 0872FREGONNTSA 0872INDULKANANTSA 0872MIMILINTSA 0872NGAANYATJARRA-GILESNTWA 0872GIBSON DESERT NORTHNTWA 0872GIBSON DESERT SOUTHNTWA 2406MUNGINDINSWNSW and QLD 2540HMAS CRESWELLNSWJervis Bay Territory 2540JERVIS BAYNSWJervis Bay Territory 2611COOLEMANACTNSW 2611BIMBERIACTNSW 2611BRINDABELLAACTNSW 2611URIARRAACTNSW 2620HUMENSWACT 2620KOWENNSWACT 2620KOWEN FORESTNSWACT 2620OAKS ESTATENSWACT 2620THARWANSWACT 2620TOP NAASNSWACT 3585MURRAY DOWNSVICNSW 3586MALLANVICNSW 3644BAROOGAVICNSW 3644LALALTYVICNSW 3691LAKE HUME VILLAGEVICNSW 3707BRINGENBRONGVICNSW 4380MINGOOLAQLDNSW 4377MARYLANDQLDNSW 4383JENNINGSQLDNSW 4385TEXASQLDNSW and QLD
Some of the postcodes above may cover two or more states. For example, postcode 2620 covers both a locality in NSW (Gundaroo) as well as a locality in the ACT (Hume), and postcode 0872 covers a number of localities across WA, SA and NT.
Three locations (Mingoola, Mungindi and Texas) straddle the NSW-Queensland border (so same town name and postcode on both sides).
Jervis Bay Territory is located on the coast of NSW. It is just south of the towns of Vincentia and Huskisson, with which it shares a postcode. Mail to the Jervis Bay Territory is addressed to the ACT.
The numerals used to show the state on each radio callsign in Australia are the same numeral as the first numeral for postcodes in that state, e.g. 2xx in New South Wales, 3xx in Victoria, etc. Radio callsigns pre-date postcodes in Australia by more than forty years.
External territories Australia's external territories are also included in Australia Post's postcode system. While these territories do not belong to any state, they are addressed as such for mail sorting:
External territoryPostal statePostcodeNorfolk IslandNSW2899Christmas IslandWA6798Cocos (Keeling) IslandsWA6799Heard and McDonald IslandsTAS7151
Three scientific bases in Antarctica operated by the Australian National Antarctic Research Expeditions share a postcode with the isolated sub-Antarctic island of Macquarie Island (part of Tasmania):
Antarctic basePostal statePostcodeCasey StationTAS7151Davis StationTAS7151Mawson StationTAS7151
There is also a "special" postcode for routing mail sent to Santa Claus:
Arctic basePostal statePostcodeNorth PoleVIC9999
State and territory capital cities Each state's capital city ends with three zeroes, while territorial capital cities end with two zeroes. Capital city postcodes were the lowest postcodes in their state or territory range, before new ranges for LVRs and PO Boxes were made available. The last numeral can usually be changed from "0" to "1" to get the postcode for General Post Office boxes in any capital city (though Perth now uses a different range of postcodes for its GPO Boxes):
CityState/TerritoryStreet AddressGPO Box Address SydneyNSW20002001 CanberraACT26002601 MelbourneVIC30003001 BrisbaneQLD40004001 AdelaideSA50005001 PerthWA60006001 HobartTAS70007001 DarwinNT08000801
Allocation within states While the first numeral of a postcode usually shows the state or territory, the second numeral usually shows a region within the state. However, postcodes with the same second numeral are not always next to each other. As an example, postcodes in the range 2200–2299 are split between the southern suburbs of Sydney and the Central Coast, Lake Macquarie and Newcastle regions of New South Wales.
Postcodes with a second numeral of "0" or "1" are almost always located within the metropolitan area of the state's capital city. Postcodes with higher second numerals are usually located in rural and regional areas. Common exceptions are where towns were rural when postcodes were first introduced in 1967, but have since been suburbanised and incorporated into metropolitan areas, e.g. Penrith, New South Wales has the postcode 2750 and Petrie, Queensland has the postcode 4502.
Within each region with the same second numeral, postcodes are usually allocated in ascending order the further one travels from the state's capital city along major highways and railways. For instance, heading north on the North Coast railway in New South Wales away from Sydney:
TownPostcodeDistance from Central Station Dungog2420 Taree2430 Kempsey2440 Coffs Harbour2450 Grafton2460 Casino2470
Major towns and cities Major towns and cities tend to have "0" as the last numeral or last two numerals, e.g. Rockhampton, Queensland has the postcode 4700 and Ballarat, Victoria has the postcode 3350. There are exceptions; the major town of Ipswich, Queensland has the postcode 4305, while Goodna, a relatively small suburb of Ipswich, is allocated 4300.
Postcode squares Australia Post used to prefer envelopes sold in Australia to have four boxes in the bottom right corner of the front of the envelope. Entering the postcode in these boxes or squares, which Australia Post calls postcode squares, enabled Australia Post to use optical character recognition software in its mail sorting machines to automatically and more quickly sort mail into postcodes, which also embeds routing information. Postcode squares were introduced in June 1990. However, more recently Australia Post has recommended not using the postcode squares at all and writing the postcode on the address line.
Other uses Many other organisations now use postcodes. Insurance companies often use postcodes when working out the cost of car and house insurance. Transport for NSW uses postcodes to give specific numbers for each bus stop in Greater Sydney. The stop number is five to seven numbers: the first four are the postcode, and the others show the bus stop (sometimes written with a space in between, e.g. "2000 108").
Many companies that produce metropolitan street maps also list the postcodes for each suburb, both in indexes and on the maps themselves. Spatial representation of postcodes is also very popular in defining sales and franchise territories.
Australian Bureau of Statistics, Australian Taxation Office and many other Federal and State government organisations publish a variety of statistics by postcode which extends the use Australia Post four digit code to many business and social planning related activities.