Home Postcode finder WA Lake Carnegie Lake Carnegie postcode WA Lake Carnegie is a locality in Western Australia covered by postcode 6646. Postcode 6646 State or territory Western Australia (WA) Region North West Suburbs Add a free Lake Carnegie business listing Be the first listing in Lake Carnegie Common questionsWhat is the postcode for Lake Carnegie?Lake Carnegie, WA has the postcode 6646.What state is Lake Carnegie in?Lake Carnegie is in Western Australia (WA).Does postcode 6646 cover more than one suburb?Yes. Postcode 6646 covers 3 localities, so the postcode alone does not identify Lake Carnegie. Browse other postcodes in Western Australia, or widen the search to every Australian postcode.