This dataset is the definitive set of territorial authority subdivision boundaries for 2017 as defined by the territorial authorities and Local Government Commission but maintained by Statistics New Zealand (the custodian). Subdivisions are set up under the Local Government Act 2002 and Local Electoral Act 2001. A subdivision is a division of a community or local board area for electoral purposes. Subdivisions are defined at meshblock level, and do not coincide with area units. A number of territorial authorities do not have subdivisions, and if they do, the subdivisions do not necessarily cover the whole territorial authority area. Subdivisions nest within community or local boards. Where a community or local board is divided into subdivisions all of the community or local board area must be included in a subdivision. Subdivisions are numbered based on their corresponding territorial authority. Each subdivision has a unique five-digit number. The first three digits refer to the territorial authority that the subdivision lies within. The following two digits are sequential, and represent the number of subdivisions within the territorial authority. For example, Southland District (073) has two subdivisions numbered 07301 and 07302. The rest of the district is not represented by a subdivision and is coded 07399 (Area Outside Subdivision).
There was a large increase in the number of subdivisions between 2010 and 2011. This is due to the creation of the Auckland Council to replace Auckland Regional Council and seven territorial authorities in 2010. Twenty-one local boards were established, a number of which contain subdivisions. There was also an increase in subdivisions between 2016 and 2017 following the three-yearly representation review.