Home Postcode finder WA Westonia Westonia postcode WA Westonia is a locality in Western Australia covered by postcode 6423. Postcode 6423 State or territory Western Australia (WA) Region Wa Subs 1 G Flds Add a free Westonia business listing More business listings in Westonia Businesses in WestoniaWestonia Primary SchoolCnr Gold & Diorite Streets · 08 90467051 Common questionsWhat is the postcode for Westonia?Westonia, WA has the postcode 6423.What state is Westonia in?Westonia is in Western Australia (WA).Does postcode 6423 cover more than one suburb?Yes. Postcode 6423 covers 4 localities, so the postcode alone does not identify Westonia. Browse other postcodes in Western Australia, or widen the search to every Australian postcode.