What is Zip Code Australia?

If you're a regular reader of the Australian media, it will not have failed to mention Australia's postal codes, often referred to as postcodes. These are four digits which identify specific parts of the country, and assist in mail sorting and delivery.

The first numeral of a postcode typically shows which state or territory the area belongs to, and the second indicates which region within that state. Some postcodes may cover two states - for example the 2620 postcode (Gundaroo) is both in NSW and in the ACT.

According to new figures released by the Australian Taxation Office, some of Australia's richest people live in the Perth suburb of Cottesloe. The top ten richest postcodes are rounded out by Northbridge in Western Australia, the Victoria suburb of Double Bay and the Sydney suburb of Hunters Hill.

ATO compiled the list by using data from 2016 Censuses, which showed each of the areas' average annual incomes. In addition, the ATO also ranked the nation's lowest earning postcodes, with 2397 - comprising Bellata, Jews Lagoon and Millie in far north NSW - taking out the bottom spot.

Postcodes are usually included after the Locality and State/Territory components of an address, on envelopes and postcards they are often pre-printed with a row of four orange square boxes in the lower right corner that can be filled in by hand when writing an address. Alternatively, most Australia Post offices will accept the postcode as a substitute for the State/Territory component.