Australian Postcode Regular Expression - AU Postcode Regex

Regex for all postcodes

/(0[8-9]|[1-9][0-9])[0-9][0-9]/

Source

https://auspost.com.au/business/marketing-and-communications/access-data-and-insights/address-data/postcode-data

Postcodes by state

0800 ... 0999, 1000 ... 2599, 2600 ... 2619, 2620 ... 2899, 2900 ... 2920, 2921 ... 2999,
 |         |    |         |    |         |    |         |    |         |    |         |    
 +-- ACT --+    +-- NSW --+    +-- ACT --+    +-- NSW --+    +-- ACT --+    +-- NSW --+


3000 ... 3999, 4000 ... 4999, 5000 ... 5999, 6000 ... 6999, 7000 ... 7999, 
 |         |    |         |    |         |    |         |    |         |    
 +-- Vic --+    +-- Qld --+    +-- SA ---+    +-- WA ---+    +-- Tas --+


8000 ... 8999, 9000 ... 9999
 |         |    |         |
 +-- Vic --+    +-- Qld --+