What are postcodes?

A postcode is a four digit number used by Australia Post to assist with mail delivery. Australia Post does not currently define geographic boundaries for postcodes. However, a number of organisations, such as PSMA Australia Limited, create geographic boundaries that aim to define the geographic extent of the mail delivery area for each postcode. Defining postcodes with a geographic boundary is an imprecise process, and this is demonstrated by the fact that there are variations in boundaries released by different organisations.

Postcodes cover most, but not all, of Australia; for example, western Tasmania is not covered by a postcode.

Because postcodes are a well-known and easily collected component of an address, they are used by many researchers and businesses as a way of linking data to a geographic area for spatial analysis. The ABS provides ‘Postcode Indexes’ that can be used to link data collected with a postcode to standard ABS geographic areas – for example, Statistical Divisions (SDs) and Remoteness Areas (RAs) within the Australian Standard Geographical Classification (ASGC) or Statistical Areas Level 4 (SA4s) and Greater Capital City Statistical Areas (GCCSAs) within the Australian Statistical Geography Standard (ASGS). This enables data to be directly compared with a range of other ABS data that is released on both the ASGC and the ASGS. For a full list of coding indexes available, please view the ‘Correspondences’ chapter of the ABS Statistical Geography website: http://www.abs.gov.au/geography.

What are ABS Postal Areas and what is their purpose?

Postal Areas (POAs) are an ABS approximation of postcodes created to enable the release of ABS data on areas that, as closely as possible, approximate postcodes. This enables the comparison of ABS data with other data collected using postcodes. POAs are approximated using one or more Statistical Areas Level 1 (SA1s) from the ASGS. SA1s are the smallest geographic areas on which Census data are released. Previously, POAs were defined using aggregations of Census Collection Districts (CCDs).

POAs are defined to cover the whole of geographic Australia. However, Unclassified POAs, which represent areas not covered by postcodes, are not represented as spatial objects in the POA digital boundaries.

POAs are incorporated into the ASGS as a non-ABS structure. These are geographic areas that approximate administrative or environmental boundaries which are not defined by the ABS, but are important to users of ABS statistics. Diagram 1 illustrates how POAs (in orange) relate to other ABS and non-ABS structures.

Diagram 1 ASGS non-ABS structures and 2011 SLA

Diagram illustrating the relationship between SSCs and other ABS and Non-ABS structures

How were POAs created?

In developing POAs, each SA1 is allocated an Australia Post postcode. POAs derived in this way only approximate Australia Post postcode boundaries. SA1 allocations are based on the distribution of dwellings, not on area. This means that an SA1 is allocated to the postcode to which it contributes the most dwellings. POAs are then formed by joining the SA1s that have been allocated the same postcode.

Allocations have been determined using the best available information on postcode boundaries. Unfortunately, official postcode boundaries have not been updated since the early 1990s and none of the more recent interpretations have been endorsed by Australia Post. Users should be aware of these limitations when using the POA classification.

Unallocated postcodes

Some Australia Post postcodes are not included in the POA classification. This occurs when no SA1 can be allocated to a particular postcode. There are two situations when this occurs where:
  • an SA1 covers two or more whole postcodes, the SA1 can be allocated to only one POA
  • more than one SA1 partially covers a postcode, but all the SA1s are allocated to other postcodes with which they also share area.

A list of delivery area postcodes not included in the POA classification is provided at the end of this document.

The POAs also exclude Australia Post postcodes that are not street delivery areas. These include post office boxes, mail back competitions, large volume receivers and specialist delivery postcodes. These postcodes are only valid for postal addresses and are not a valid location for population data.

POAs that cross state or territory borders

Where POAs cross state or territory borders, standard Census products will provide data for the entire POA. The following table lists these POAs.

Postal Area Postal Areas that cross state or territory borders
POA 0872 Postal Area 0872 crosses into NT, SA and WA
POA 2540 Postal Area 2540 crosses NSW and OT (Jervis Bay)
POA 2618 Postal Area 2618 crosses NSW and ACT
POA 2620 Postal Area 2620 crosses NSW and ACT
POA 3585 Postal Area 3585 crosses Vic. and NSW
POA 3644 Postal Area 3644 crosses Vic. and NSW
POA 4383 Postal Area 4383 crosses Qld and NSW
POA 4825 Postal Area 4825 crosses Qld and NT


Working with data on POAs

When working with data on POAs, it is important to remember that the POAs are approximations, using SA1s, of the postcode boundaries and that the data relate to the POA boundary and not to the postcode boundary. The POA classification also excludes some postcodes and therefore, there will be no Census data for these postcodes.

In some cases, users of Census data may have trouble reconciling their own postcode based statistics with Census data because:
  • Many respondents mis-report their postcode.
  • It is difficult to determine the 'correct' postcode for some respondents, particularly where post office boxes and rural delivery services are concerned.
  • POA Census data reflect either the location of a person’s usual residence (for usual residence data) or the location of a person on Census night (as enumerated data). By contrast, many non-ABS datasets only record the postcode of a person's mailing address. Since many people have different mailing and residential addresses the datasets are difficult to reconcile.
  • Postcode boundaries change over time and it can take a long time for respondents and coding systems to adjust to a change in a postcode. This causes problems when working with postcode-based data taken from different reference periods, as the changes to the boundaries can be difficult to reconcile with changes in the population.

What data will be available on POAs?

Data from the 2011 Census of Population and Housing will be available for POAs.

Where can I get the POA boundaries?

POA boundaries are available in MapInfo Interchange and ESRI Shapefile formats and can be downloaded from the ‘ABS Geography Publications’ chapter of the ABS Statistical Geography website: http://www.abs.gov.au/geography.

DataPacks contain 2011 Census Community Profile data for all of Australia and corresponding digital boundary map files. To find out more about DataPacks, visit the DataPacks page.

Where can I get further information?

A detailed discussion of the POAs and the criteria used in their design can be found at: Australian Statistical Geography Standard (ASGS): Volume 3 – Non ABS Structures, July 2011 (cat. no. 1270.0.55.003).

More information on the ASGS and ABS Statistical Geography can be found at: Australian Statistical Geography Standard: Volume 1 Main Structure and Greater Capital City Statistical Areas, July 2011 (cat. no. 1270.0.55.001) or by visiting the ABS Statistical Geography website: http://www.abs.gov.au/geography.

Any questions or comments can be emailed to geography@abs.gov.au.

Unallocated delivery area postcodes

The following tables list the delivery area postcodes for each state and territory that were not included in the POA classification.

New South Wales
Australia Post
postcode
Locality
2091 HMAS PENGUIN
2123 PARRAMATTA
2309 DANGAR
2331 Multiple Localities
2356 GWABEGAR
2379 Multiple Localities
2387 Multiple Localities
2398 GURLEY
2411 CROPPA CREEK
2522 UNIVERSITY OF WOLLONGONG
2624 PERISHER VALLEY
2734 Multiple Localities
2755 RICHMOND RAAF
2818 Multiple Localities
2826 Multiple Localities
2838 GOODOOGA
2899 NORFOLK ISLAND

 

Victoria
Australia Post
postcode
Locality
3050 ROYAL MELBOURNE HOSPITAL
3271 Multiple Localities
3279 Multiple Localities
3322 CRESSY
3323 Multiple Localities
3415 MIRAM
3432 BOLINDA
3487 LASCELLES
3488 Multiple Localities
3489 TEMPY
3506 COWANGIE
3529 Multiple Localities
3565 KOTTA
3576 DURHAM OX
3583 TRESCO
3599 BOUNDARY BEND
3607 TABILK
3647 DOOKIE COLLEGE
3665 Multiple Localities
3704 KOETONG
3708 TINTALDRA
3718 MOLESWORTH
3738 OVENS
3762 BYLANDS
3893 Multiple Localities
3946 BENA
3964 PORT FRANKLIN
3967 HEDLEY
3990 GLEN FORBES

 

Queensland
Australia Post
postcode
Locality
4029 ROYAL BRISBANE HOSPITAL
4222 GRIFFITH UNIVERSITY
4384 LIMEVALE
4418 GULUGUBA
4423 Multiple Localities
4426 Multiple Localities
4461 MUCKADILLA
4467 Multiple Localities
4471 CLAVERTON
4474 ADAVALE
4475 CHEEPIE
4479 COOLADDI
4482 BIRDSVILLE
4489 WYANDRA
4491 EULO
4493 HUNGERFORD
4697 RAGLAN
4704 Multiple Localities
4706 OGMORE
4732 Multiple Localities
4736 JUNDAH

 

South Australia
Australia Post
postcode
Locality
5150 Multiple Localities
5273 AVENUE RANGE
5306 WYNARKA
5310 Multiple Localities
5418 Multiple Localities
5420 Multiple Localities
5432 Multiple Localities
5455 HILLTOWN
5471 GULNARE
5493 YONGALA
5632 Multiple Localities
5651 KYANCUTTA
5653 YANINEE
5655 Multiple Localities
5660 Multiple Localities
5661 Multiple Localities
5671 Multiple Localities
5730 Multiple Localities
5733 Multiple Localities

 

Western Australia
Australia Post
postcode
Locality
6034 EGLINTON
6038 ALKIMOS
6223 BENGER
6228 WATERLOO
6243 Multiple Localities
6252 MULLALYUP
6351 Multiple Localities
6356 Multiple Localities
6357 PINGARING
6361 Multiple Localities
6363 Multiple Localities
6372 YEALERING
6384 PANTAPIN
6385 KWOLYIN
6411 Multiple Localities
6412 Multiple Localities
6414 NANGEENAN
6419 ARDATH
6420 Multiple Localities
6422 WALGOOLAN
6424 Multiple Localities
6427 KOOLYANOBBING
6428 BABAKIN
6446 GRASS PATCH
6452 Multiple Localities
6463 BENJABERRING
6465 MANMANNING
6466 CADOUX
6467 BURAKIN
6470 KULJA
6473 Multiple Localities
6476 GABBIN
6480 NUKARNI
6487 Multiple Localities
6489 Multiple Localities
6504 MOOLIABEENEE
6506 MOGUMBER
6512 Multiple Localities
6571 YERECOIN
6572 PIAWANING
6574 Multiple Localities
6605 KONDUT
6613 BUNTINE
6614 MAYA
6616 LATHAM
6625 MERKANOOKA
6627 CANNA
6631 PINDAR
6632 Multiple Localities
6711 THEVENARD ISLAND
6712 BARROW ISLAND
6731 COCKATOO ISLAND
6733 KOOLAN ISLAND

 

Tasmania
Australia Post
postcode
Locality
7001 HOBART
7119 STONOR
7139 STRATHGORDON
7174 COPPING
7175 Multiple Localities
7185 PREMAYDENA
7187 KOONYA
7466 GORMANSTON

 

Northern Territory
Australia Post
postcode
Locality
0834 VIRGINIA
0839 COOLALINGA
0909 CHARLES DARWIN UNIVERSITY

 

Australian CapitalTerritory
No unallocated Australia Post postcodes.

 

Other Territories
No unallocated Australia Post postcodes.