Each Australian capital city's CBD has a well-known postcode, and the same pattern repeats nationally: capital CBDs start at x000 (e.g. 3000 for Melbourne). Here's a detailed breakdown for every state and territory capital.
Sydney
NSWPopulation: ~5.3 million
Sydney CBD, including the central business district, The Rocks, and Haymarket. The Greater Sydney metro area spans postcodes 2000–2234.
Melbourne
VICPopulation: ~5.2 million
Melbourne CBD and Docklands. The greater Melbourne metro area covers postcodes 3000–3207 and 3800–3978.
Brisbane
QLDPopulation: ~2.6 million
Brisbane CBD and the inner-city area. The Brisbane LGA spans postcodes 4000–4179.
Adelaide
SAPopulation: ~1.4 million
Adelaide CBD, including the city of Adelaide. Greater Adelaide spans postcodes 5000–5168.
Perth
WAPopulation: ~2.2 million
Perth CBD and the inner city. Greater Perth spans postcodes 6000–6215.
Hobart
TASPopulation: ~240,000
Hobart CBD and the central Hobart area. Greater Hobart covers postcodes 7000–7054.
Darwin
NTPopulation: ~148,000
Darwin CBD. Darwin and the surrounding area spans postcodes 0800–0835.
Canberra
ACTPopulation: ~470,000
Canberra CBD (Civic). The ACT spans postcodes 2600–2617 and 2900–2920. Note: 0200 is used for the ANU campus.
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