Home Postcode finder WA Mitchell Plateau Mitchell Plateau postcode WA Mitchell Plateau is a locality in Western Australia covered by postcode 6740. Postcode 6740 State or territory Western Australia (WA) Region North West Suburbs Add a free Mitchell Plateau business listing Be the first listing in Mitchell Plateau Common questionsWhat is the postcode for Mitchell Plateau?Mitchell Plateau, WA has the postcode 6740.What state is Mitchell Plateau in?Mitchell Plateau is in Western Australia (WA).Does postcode 6740 cover more than one suburb?Yes. Postcode 6740 covers 6 localities, so the postcode alone does not identify Mitchell Plateau. Browse other postcodes in Western Australia, or widen the search to every Australian postcode.