Home Postcode finder WA Cullalla Cullalla postcode WA Cullalla is a locality in Western Australia covered by postcode 6503. Postcode 6503 State or territory Western Australia (WA) Region Wa Subs 4 Coast Add a free Cullalla business listing Be the first listing in Cullalla Common questionsWhat is the postcode for Cullalla?Cullalla, WA has the postcode 6503.What state is Cullalla in?Cullalla is in Western Australia (WA).Does postcode 6503 cover more than one suburb?Yes. Postcode 6503 covers 20 localities, so the postcode alone does not identify Cullalla. Browse other postcodes in Western Australia, or widen the search to every Australian postcode.