Reduce the list, select first 2 letters of the city:
Listing cities (22 place(s)). Select the City to see the postcode(s):
Listing cities (22 place(s)). Select the City to see the postcode(s):
Position: Postcodes > Australia > Western Australia > O.... >
Postcode finder: Australia, List of the cities starting with O. Australia Western Australia Postcodes (Desktop version).