Postcodes in Australia

Overview

Postcodes are an important part of Australia's postal system, designed to streamline mail sorting and delivery processes across the country. Introduced in 1967, they replaced earlier postal systems like alphanumeric postal codes and zone numbers, creating a standardised system that is still in use today.

What Are Postcodes?

Postcodes in Australia are a four-digit number used by Australia Post to identify specific geographic regions or types of delivery points. Each state and territory in Australia has its own distinct postcode ranges, ensuring a clear and logical system for mail distribution.

How Are Postcodes Used?

Postcodes in Australia serve several purposes:

  • Mail Sorting and Delivery: Postcodes help postal workers quickly determine the destination of letters and parcels, minimising delays and errors in delivery. Automated sorting machines rely on these codes for accurate processing.
  • Defining Delivery Areas: Postcodes are used to define delivery zones, often corresponding to suburbs, towns, or regions. Large organizations and government bodies also use postcodes for data collection, service planning, and demographic analysis.
  • Special Purposes: Some postcodes are reserved for specific uses, such as large-volume receivers (LVRs) or PO Boxes. For example, postcodes in the 8000–8999 range in Victoria are designated for LVRs and PO Boxes rather than physical addresses.
Do Postcodes Always Relate to a Physical Place?

Interestingly, postcodes in Australia do not always correspond to a single physical location. While most postcodes represent suburbs or towns, there are exceptions:

  • Shared Postcodes: In some areas, a single postcode may cover multiple towns or localities.
  • Non-Sequential Assignment: Postcodes are not always assigned in numerical order. Historical factors, population growth, and administrative changes have all contributed to the current numbering system.
  • Non-Physical Locations: Postcodes may also be assigned to PO Boxes, corporate entities, or virtual locations without a specific geographic boundary.