2970.0.55.016 - 2001 Census of Population and Housing - Fact Sheet: Postcodes and Census Data, 2001  
ARCHIVED ISSUE Released at 11:30 AM (CANBERRA TIME) 09/10/2006  Reissue
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REISSUE - WA Postcodes 6798 and 6799 were incorrectly listed as Unallocated Postcodes, these two postcodes have been removed from the list. No other changes have been applied to this product.


Postcodes and Census Data


1 Postcodes and postal areas

A postcode is a four digit number used by Australia Post to assist with mail delivery. As it is readily available on the end of each postal address, many researchers and businesses use postcode as a make shift geographic region for aggregation and analysis of address based data. The desire to compare such data to census data in turn creates demand for census data aggregated by postcode. Census data are collected on Collection Districts (CDs) which, for several reasons, are not compatible with postcodes. The Australian Bureau of Statistics (ABS) has, however developed a Census Geographic Area classification known as Postal Areas which approximate the area of those postcodes where people live.


Postal Area

Postal Areas are created by allocating whole CDs to Australia Post postcode areas on a 'best fit' basis (See Statistical Geography: Volume 2 - Census Geographic Areas (Cat. no. 2905.0) available July 2002). Postal Areas derived in this way only approximate Australia Post postcodes.

In developing Postal Areas each CD is allocated an Australia Post postcode. Allocations are done on the basis of population and not area. This means that a CD is allocated to a postcode if the majority of the population in that CD is contained within that postcode. Postal Areas are then formed by joining together the CDs that have been allocated the same postcode.

Allocations have been determined using the best available information on postcode boundaries. Unfortunately official maps of 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, therefore, be aware of the limitations of the Postal Area classification.

Some Australia Post postcodes are not included in the Postal Area classification. For instance, in some cases when applying the 'best fit' principle there is no CD which can be allocated to a particular Australia Post postcode. This occurs in two cases:

  • where a CD covers two or more whole postcodes, the CD can be allocated to only one Postal Area ; or
  • where more than one CD partially covers a postcode but all the CDs are allocated to other postcodes with which they also share area.
The Postal Area classification also excludes Australia Post post codes which are not street delivery areas. These include post office box, 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.


Postal Areas that cross State/Territory borders:

Where Postal Areas cross State/Territory borders standard census products will provide data for the entire Postal Area.

NSW-Postal Area 2620 crosses into the ACT, 2406 crosses into Qld and 2540 crosses into Jervis Bay (Other Territories).
Vic-Postal Areas 3500, 3585 and 3644 cross into NSW.
Qld-Postal Area 4825 crosses into NT.
SA-None
WA-None
Tas.-None
NT-Postal Area 872 crosses into SA.
ACT-Postal Area 2618 crosses into NSW.
OT -N/A


2 Digital boundaries

Postal Area digital boundaries will be available as part of the Census Geographic Areas 2001, Australia CD-ROM. This will be available at the end of June 2002.

All digital boundaries are supplied as 'all points' boundaries in MapInfo Export (.mif/.mid) format. These are suitable for import into geographic information systems and desktop mapping packages. All spatial data released by the ABS after August 2001 are based on the Geocentric Datum of Australia,1994 (GDA94). For more information on GDA94 see the Fact sheet Geocentric Datum of Australia and Australian Bureau of Statistics Boundaries.


3 Comparing other postcode based statistics to census statistics

Users of census data can have trouble reconciling their own postcode based statistics with census statistics because:
  • many respondents mis-report their postcode;
  • it is also difficult to say what the 'correct' postcode for some respondents should be, especially when considering post office boxes and rural delivery services. Census data are based either upon the Postal Area of the residence where a person was enumerated or the Postal Area where they normally reside. 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; and
  • 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 are difficult to reconcile with changes in the population.


Comparing non-ABS data on postcode with ABS data on Postal Area as enumerated

The primary consideration when doing a comparison with Census data based on the Postal Area classification is that the Postal Areas are derived using a 'best fit' of whole CDs. The census data are correct for the Postal Area but the Postal Area only approximates the area of the postcode. The Postal Area classification also excludes some postcodes and as such there will be no census data for these postcodes.


Postal Area of Usual Address Census Night (POCUCP)

Postal Area of Usual Address Census Night (POCUCP) is a census variable which identifies the Postal Area of the person's usual address. For people counted at home, the value for POCUCP is determined from the CD of the residence. For people enumerated away from home, their usual address is coded to a CD where possible and then the Postal Area of that CD is used. Where a person does not state his/her place of usual residence they are coded to Postal Area undefined. For example:

  • 2999
    NSW Postal Area undefined; and
  • 3999
    Vic. Postal Area undefined.


4 Alternatives to postcode/postal area census data

In previous censuses Usual Address data were only available by Statistical Local Area (SLA) and Postal Area. For the 2001 Census data will be available by CD of usual residence. Users of Census data who previously resorted to Postal Area data may instead wish to consider using CD of usual residence.

For the 2001 Census, State Suburbs (See Statistical Geography: Volume 2 - Census Geographic Areas (Cat. no. 2905.0) available July 2002) have been defined for all capital cities except Canberra, Brisbane and Darwin. In these cities SLAs are closely related to suburbs. Many users of Postal Area data may find that suburb is a more convenient and more readily recognisable geographical area for their purposes. In many cities there is a many to one relationship between suburb and postcode so in theses cases suburb data also provide a finer level of geographical resolution.


Unallocated Australia Post Postcodes

Below is a list of Australia Post postcodes for street delivery areas which are not represented in the ABS 2001 Postal Area Classification. Australia Post postcodes for post office boxes, mail back competitions, large volume receivers and specialist delivery postcodes, which are also not represented in the ABS 2001 Postal Area Classification, have not been listed.


Postcode,State

2127,NSW
2308,NSW
2309,NSW
2356,NSW
2649,NSW
2734,NSW
2899,NSW

3005,VIC
3008,VIC
3010,VIC
3050,VIC
3217,VIC
3267,VIC
3273,VIC
3275,VIC
3278,VIC
3279,VIC
3301,VIC
3329,VIC
3378,VIC
3384,VIC
3385,VIC
3387,VIC
3399,VIC
3415,VIC
3422,VIC
3432,VIC
3488,VIC
3489,VIC
3494,VIC
3522,VIC
3565,VIC
3576,VIC
3581,VIC
3590,VIC
3599,VIC
3617,VIC
3637,VIC
3663,VIC
3704,VIC
3718,VIC
3738,VIC
3739,VIC
3755,VIC
3852,VIC
3873,VIC
3893,VIC
3928,VIC
3954,VIC

4230,QLD
4345,QLD
4353,QLD
4363,QLD
4364,QLD
4365,QLD
4372,QLD
4375,QLD
4376,QLD
4378,QLD
4381,QLD
4384,QLD
4423,QLD
4424,QLD
4461,QLD
4471,QLD
4479,QLD
4493,QLD
4611,QLD
4676,QLD
4694,QLD
4697,QLD
4704,QLD
4706,QLD
4710,QLD
4712,QLD
4713,QLD
4723,QLD
4728,QLD
4801,QLD
4849,QLD

5150,SA
5220,SA
5221,SA
5263,SA
5269,SA
5273,SA
5303,SA
5306,SA
5310,SA
5312,SA
5410,SA
5414,SA
5416,SA
5418,SA
5455,SA
5471,SA
5493,SA
5510,SA
5552,SA
5630,SA
5632,SA
5651,SA
5653,SA
5660,SA
5730,SA

6036,WA
6038,WA
6090,WA
6221,WA
6223,WA
6228,WA
6232,WA
6240,WA
6243,WA
6252,WA
6313,WA
6322,WA
6326,WA
6357,WA
6358,WA
6368,WA
6384,WA
6385,WA
6394,WA
6396,WA
6403,WA
6411,WA
6412,WA
6413,WA
6414,WA
6419,WA
6420,WA
6421,WA
6422,WA
6424,WA
6427,WA
6428,WA
6445,WA
6446,WA
6462,WA
6465,WA
6466,WA
6467,WA
6470,WA
6473,WA
6489,WA
6505,WA
6506,WA
6512,WA
6564,WA
6568,WA
6571,WA
6572,WA
6574,WA
6614,WA
6616,WA
6625,WA
6627,WA
6628,WA
6632,WA
6711,WA
6712,WA
6723,WA
6733,WA
6761,WA
6762,WA


7001,TAS
7119,TAS
7139,TAS
7151,TAS
7174,TAS
7175,TAS
7176,TAS
7183,TAS
7185,TAS
7187,TAS
7257,TAS

0840,NT
0853,NT