Home Postcode finder SA Hammond Hammond postcode SA Hammond is a locality in South Australia covered by postcode 5431. Postcode 5431 State or territory South Australia (SA) Region SA Outer Suburbs Add a free Hammond business listing Be the first listing in Hammond Common questionsWhat is the postcode for Hammond?Hammond, SA has the postcode 5431.What state is Hammond in?Hammond is in South Australia (SA).Does postcode 5431 cover more than one suburb?Yes. Postcode 5431 covers 14 localities, so the postcode alone does not identify Hammond. Browse other postcodes in South Australia, or widen the search to every Australian postcode.