Home Postcode finder WA Diamond Tree Diamond Tree postcode WA Diamond Tree is a locality in Western Australia covered by postcode 6258. Postcode 6258 State or territory Western Australia (WA) Region Wa Subs 3 Sth Rd Add a free Diamond Tree business listing Be the first listing in Diamond Tree Common questionsWhat is the postcode for Diamond Tree?Diamond Tree, WA has the postcode 6258.What state is Diamond Tree in?Diamond Tree is in Western Australia (WA).Does postcode 6258 cover more than one suburb?Yes. Postcode 6258 covers 22 localities, so the postcode alone does not identify Diamond Tree. Browse other postcodes in Western Australia, or widen the search to every Australian postcode.