Home Postcode finder WA Sunnyside Sunnyside postcode WA Sunnyside is a locality in Western Australia covered by postcode 6256. Postcode 6256 State or territory Western Australia (WA) Region Wa Subs 3 Sth Rd Add a free Sunnyside business listing Be the first listing in Sunnyside Common questionsWhat is the postcode for Sunnyside?Sunnyside, WA has the postcode 6256.What state is Sunnyside in?Sunnyside is in Western Australia (WA).Does postcode 6256 cover more than one suburb?Yes. Postcode 6256 covers 6 localities, so the postcode alone does not identify Sunnyside. Browse other postcodes in Western Australia, or widen the search to every Australian postcode.