Home Postcode finder WA North Walpole North Walpole postcode WA North Walpole is a locality in Western Australia covered by postcode 6398. Postcode 6398 State or territory Western Australia (WA) Region Wa Subs 2 Gsr Add a free North Walpole business listing Be the first listing in North Walpole Common questionsWhat is the postcode for North Walpole?North Walpole, WA has the postcode 6398.What state is North Walpole in?North Walpole is in Western Australia (WA).Does postcode 6398 cover more than one suburb?Yes. Postcode 6398 covers 3 localities, so the postcode alone does not identify North Walpole. Browse other postcodes in Western Australia, or widen the search to every Australian postcode.