Home Postcode finder SA Clayton Bay Clayton Bay postcode SA Clayton Bay is a locality in South Australia covered by postcode 5256. Postcode 5256 State or territory South Australia (SA) Region Sa Subs Near 2 Add a free Clayton Bay business listing Be the first listing in Clayton Bay Common questionsWhat is the postcode for Clayton Bay?Clayton Bay, SA has the postcode 5256.What state is Clayton Bay in?Clayton Bay is in South Australia (SA).Does postcode 5256 cover more than one suburb?Yes. Postcode 5256 covers 5 localities, so the postcode alone does not identify Clayton Bay. Browse other postcodes in South Australia, or widen the search to every Australian postcode.