Home Postcode finder WA North Bannister North Bannister postcode WA North Bannister is a locality in Western Australia covered by postcode 6390. Postcode 6390 State or territory Western Australia (WA) Region Wa Subs 2 Gsr Add a free North Bannister business listing Be the first listing in North Bannister Common questionsWhat is the postcode for North Bannister?North Bannister, WA has the postcode 6390.What state is North Bannister in?North Bannister is in Western Australia (WA).Does postcode 6390 cover more than one suburb?Yes. Postcode 6390 covers 11 localities, so the postcode alone does not identify North Bannister. Browse other postcodes in Western Australia, or widen the search to every Australian postcode.