Home Postcode finder WA The Plains The Plains postcode WA The Plains is a locality in Western Australia covered by postcode 6237. Postcode 6237 State or territory Western Australia (WA) Region Wa Subs 3 Sth Rd Add a free The Plains business listing Be the first listing in The Plains Common questionsWhat is the postcode for The Plains?The Plains, WA has the postcode 6237.What state is The Plains in?The Plains is in Western Australia (WA).Does postcode 6237 cover more than one suburb?Yes. Postcode 6237 covers 6 localities, so the postcode alone does not identify The Plains. Browse other postcodes in Western Australia, or widen the search to every Australian postcode.