Home Postcode finder WA Red Gully Red Gully postcode WA Red Gully 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 Red Gully business listing Be the first listing in Red Gully Common questionsWhat is the postcode for Red Gully?Red Gully, WA has the postcode 6503.What state is Red Gully in?Red Gully 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 Red Gully. Browse other postcodes in Western Australia, or widen the search to every Australian postcode.