Home Postcodes by state WA 6423 Postcode 6423 6423 is the postcode for 4 localities in WA: Boodarockin, Carrabin, Warrachuppin and Westonia. Localities with postcode 6423BoodarockinWACarrabinWAWarrachuppinWAWestoniaWA Postcode 6423 State or territory Western Australia (WA) Localities 4 Council area Westonia Council area based on Australian Bureau of Statistics data (ASGS Edition 3), CC BY 4.0. Postcode 6422 · Postcode 6424