Australian address format checker
The Australian address format is unit and street number, street name and type, then locality, state and a four-digit postcode, written on an envelope as 3/45 COLLINS STREET over MELBOURNE VIC 3000. Paste an address in any shape and see it split into those fields, with street types written out, the state normalised, the postcode checked against the state, and the envelope layout. Runs in your browser; nothing is sent anywhere.
This checker formats; it does not verify. Whether this address exists in G-NAF, and its coordinates, is what address verification answers. Nothing you type here leaves your browser.
The Australian postal address format, briefly
An Australian address has a fixed structure, and G-NAF, the national address file, records it as separate parts: an optional unit (flat) and level, a street number, a street name and a street type, then the locality, state and postcode. On an envelope Australia Post wants the unit and street number together with a slash, the street type in full, and the locality in capitals with the state and postcode on the final line.
3/45 COLLINS STREET
MELBOURNE VIC 3000
The mistakes we see most in stored data: postcodes held as integers (Darwin 0800 becomes 800), street numbers held as integers (12A and 12-14 cannot be), unit and street number concatenated into one field, and street types abbreviated one way on input and another on output. The storage guide has a schema that avoids all four, and the postcode validation post has the regex and the ranges.
Formatting is not verifying
This tool cannot tell you whether 45 Collins Street exists, or that a typed suburb matches its postcode in the real world. That takes the dataset. The WattleAddr API’s verify endpoint matches free text against G-NAF and returns the canonical record, a verdict, a per-field status and coordinates; the interactive reference lets you try it without a key.
Questions
What is the correct format for an Australian address?
Australia Post asks for the recipient, then the unit and street number (unit first, separated by a slash, for example 3/45 Collins Street), then the locality in capitals followed by the state abbreviation and the four-digit postcode on the last line, with no punctuation: 3/45 COLLINS STREET on one line and MELBOURNE VIC 3000 on the next. Level goes on its own line above the street. Street types may be written in full or with Australia Post’s standard abbreviations; G-NAF stores them in full.
Why does a postcode need to be stored as text?
Because Northern Territory and some ACT postcodes start with a zero. Darwin is 0800; stored as a number it becomes 800, and every export, label and lookup that reads it back is wrong. The same applies to street numbers, which can be 12A or 12-14, and to units, which can be letters.
Does this tool verify that the address exists?
No. It parses and formats what you typed using rules, in your browser, without sending it anywhere. Verifying that an address exists in Australia, correcting it and returning its coordinates is what the WattleAddr verify endpoint does against the G-NAF dataset, which is a different thing and the reason the tool links there.
What are the Australian state abbreviations and postcode ranges?
NSW 1000 to 2599 and 2619 to 2899 (plus 2921 to 2999); ACT 0200 to 0299, 2600 to 2618 and 2900 to 2920; VIC 3000 to 3999 and 8000 to 8999; QLD 4000 to 4999 and 9000 to 9999; SA 5000 to 5999; WA 6000 to 6797 and 6800 to 6999; TAS 7000 to 7999; NT 0800 to 0999. A few ranges cross borders, so an unusual pairing is worth a check rather than automatically wrong.