Postcodes are used in Australia for the purposes of sorting and directing mail. All postcodes in Australia consist of four numbers and are placed at the end of the address. Australian postcodes are allocated and managed by Australia Post.

History

Postcodes were introduced in Australia in 1967 by the Postmaster-General's Department (PMG), the predecessor of Australia Post. They replaced earlier postal sorting systems, such as Melbourne's alphanumeric codes (e.g., N3, E5) and a similar system once used in rural and regional New South Wales.

Format

Australian Postcodes are four digits long, and written after the name of the city, suburb, or town, and the state or territory:^[1]

Mr John Smith

400 Kent Street

SYDNEY NSW 2000

Geography

Australian postcodes are routing information, and while they are often associated with a single bounded geographical area (e.g. suburb or town) they are not always contiguous areas. They sometimes have quite complex geography, especially in areas beyond the urban fringe (e.g. the southern Queensland 4352 postcode, or the south-western Victoria 3221 postcode). Some postcodes cover large populations (e.g., postcode 4350 serving some 100,000 people in the City of Toowoomba), while other postcodes have much smaller populations, even in urban areas. The postcodes range from as low as 0200 (for the Australian National University) to 9729 (mail addressed to the Gold Coast City Council).

Some postcodes are associated with a single town or suburb (e.g. 6160 belongs only to Fremantle, Western Australia), while other postcodes are shared by many localities (e.g. 2570 belongs to twenty-two towns and suburbs around Camden, New South Wales).

Some towns and suburbs have two postcodes – one for street deliveries and one for post office boxes. For instance, a street address in the Sydney suburb of Parramatta would be written thus:

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 corporations, government departments and other institutions receive large volumes of mail, and are entitled to their own postcode as a Large Volume Receiver (LVR), e.g. the Royal Brisbane and Women's Hospital has the postcode 4029. More postcode ranges were made available for LVRs in the 1990s, though LVRs do not necessarily use postcodes in these new ranges.

Allocation

States and territories

The first one or two digits generally denotes the state or territory that the postcode belongs to:^[2]

State/Territory	Abbreviation	Postcode range
New South Wales	NSW	1000—1999 (LVRs and PO Boxes only) 2000—2599 2620—2898 2921—2999
Australian Capital Territory	ACT	0200—0299 (LVRs and PO Boxes only) 2600—2619 2900—2920
Victoria	VIC	3000—3999 8000—8999 ''(LVRs and PO Boxes only)
Queensland	QLD	4000—4999 9000—9999 (LVRs and PO Boxes only)
South Australia	SA	5000—5799 5800—5999 (LVRs and PO Boxes only)
Western Australia	WA	6000—6797 6800—6999 (LVRs and PO Boxes only)
Tasmania	TAS	7000—7799 7800—7999 (LVRs and PO Boxes only)
Northern Territory	NT	0800—0899 0900—0999 (LVRs and PO Boxes only)

Some exceptions to these postcode ranges occur in the vicinity of state and territory borders, where Australia Post finds it more convenient to direct mail through a nearby post office that is across the border:

Postcode	Suburb	State Derived from Postcode Ranges	Actual State for this Suburb
0872	ERNABELLA	NT	SA
0872	FREGON	NT	SA
0872	INDULKANA	NT	SA
0872	MIMILI	NT	SA
0872	NGAANYATJARRA-GILES	NT	SA
0872	FGIBSON DESERT NORTH	NT	WA
0872	FGIBSON DESERT SOUTH	NT	WA
2540	HMAS CRESWELL	NSW	Jervis Bay Territory
2540	JERVIS BAY	NSW	Jervis Bay Territory
2611	BRINDABELLA	ACT	NSW
2611	URIARRA	ACT	NSW
2620	HUME	NSW	ACT
2620	KOWEN FOREST	NSW	ACT
2620	OAKS ESTATE	NSW	ACT
2620	THARWA	NSW	ACT
2620	TOP NAAS	NSW	ACT
3500	PARINGI	VIC	NSW
3585	MURRAY DOWNS	VIC	NSW
3586	MALLAN	VIC	NSW
3644	BAROOGA	VIC	NSW
3644	LALALTY	VIC	NSW
3707	BRINGENBRONG	VIC	NSW

Some or all of the postcodes above may span two states. For example postcode 2620 covers both a suburb in NSW (Gundaroo) as well as a suburb in the ACT (Hume) - the postcode is within the ACT range.

Jervis Bay Territory, previously an exclave of the ACT but now a separate territory, is geographically located on the coast of NSW, just south of the towns of Vincentia and Huskisson, with which it shares a postcode. Mail to the Jervis Bay Territory is still addressed to the ACT.

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 routing purposes:

External territory	Postal state	Postcode
Norfolk Island	NSW	2899
Christmas Island	WA	6798
Cocos (Keeling) Islands	WA	6799

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 base	Postal state	'''Postcode
Casey Station	TAS	7151
Davis Station	TAS	7151
Mawson Station	TAS	7151

State and territory capital cities

Each state or territory's capital city ends with two zeroes or three 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 in more recent times. The last digit can usually be changed from "0" to "1" to obtain the postcode for General Post Office boxes in any capital city (though Perth now uses a different range of postcodes for its GPO Boxes):

City	State/Territory	Street Address		GPO Box Address
Sydney	NSW	2000		2001
Canberra	ACT	2600		2601
Melbourne	Vic	3000		3001
Brisbane	Qld	4000		4001
Adelaide	SA	5000		5001
Perth	WA	6000		6837—6848
Hobart	Tas	7000		7001
Darwin	NT	0800		0801

Allocation within states

While the first digit of a postcode usually indicates the state or territory, the second digit usually denotes a region within the state. However, postcodes with the same second digit do not always form to a geographically contiguous area. As an example, postcodes in the range 2200—2299 are split between the southern suburbs of Sydney and the Central Coast of New South Wales.

Postcodes with a second digit of "0" or "1" are almost always located within the metropolitan area of the state's capital city. Postcodes with higher second digits are usually located in rural and regional areas. Common exceptions are where towns were considered 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 digit, postcodes tend to increase 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:

Town	Postcode	Distance from Central Station[3]
Dungog	2420	245km
Taree	2430	378km
Kempsey	2440	503km
Coffs Harbour	2450	607km
Grafton	2460	695km
Casino	2470	805km

Major towns and cities

Major towns and cities tend to have "0" as the last digit or last two digits, e.g. Rockhampton, Queensland has the postcode 4700 and Ballarat, Victoria has the postcode 3350. There are exceptions; for instance, the major town of Ipswich, Queensland has the postcode 4305, while Goodna, a relatively unimportant suburb of Ipswich, is allocated 4300.

Postcode Squares

Post Office Preferred envelopes sold in Australia contain four squares in the bottom right corner of the front of the envelope. These squares, referred to by Australia Post as Postcode Squares, contain the destination postcode for hand-addressed mail. This is for the purpose of Australia Post's automated mail-sorting equipment, which uses optical character recognition software. Postcode Squares were introduced in the 1990s.

Australia Post recommends that Postcode Squares should not be used for machine-addressed mail, or mail destined overseas.

Other uses

Since their introduction, many organisations other than Australia Post have used postcodes in their operations. Insurance companies often use postcodes when calculating car and house insurance premiums. The NSW Ministry of Transport uses postcodes to assign specific numbers for each bus stop in Greater Sydney.

See also

1. List of postcodes in the Australian Capital Territory
2. List of postcodes in New South Wales
3. List of postcodes in Queensland
4. List of postcodes in South Australia
5. List of postcodes in Tasmania
6. List of postcodes in Victoria
7. List of postcodes in Western Australia
8. List of postcodes in the Northern Territory

External links

• Australia Post
• Australia Post: Postcode Search
• Australian Postal Code Database
• Australian Post Code Lookup with Geographic Information
• AussiePostCodes Search

References