Home Postcode finder WA East Murchison East Murchison postcode WA East Murchison is a locality in Western Australia covered by postcode 6640. Postcode 6640 State or territory Western Australia (WA) Region North West Suburbs Add a free East Murchison business listing Be the first listing in East Murchison Common questionsWhat is the postcode for East Murchison?East Murchison, WA has the postcode 6640.What state is East Murchison in?East Murchison is in Western Australia (WA).Does postcode 6640 cover more than one suburb?Yes. Postcode 6640 covers 5 localities, so the postcode alone does not identify East Murchison. Browse other postcodes in Western Australia, or widen the search to every Australian postcode.