Home Postcode finder WA Walgoolan Walgoolan postcode WA Walgoolan is a locality in Western Australia covered by postcode 6422. Postcode 6422 State or territory Western Australia (WA) Region Wa Subs 1 G Flds Add a free Walgoolan business listing Be the first listing in Walgoolan Common questionsWhat is the postcode for Walgoolan?Walgoolan, WA has the postcode 6422.What state is Walgoolan in?Walgoolan is in Western Australia (WA).Does postcode 6422 cover more than one suburb?No. Postcode 6422 covers Walgoolan only, which is unusual - most Australian postcodes cover several localities. Browse other postcodes in Western Australia, or widen the search to every Australian postcode.