Home Postcode finder SA Hartley Hartley postcode SA Hartley is a locality in South Australia covered by postcode 5255. Postcode 5255 State or territory South Australia (SA) Region Sa Subs Near 2 Add a free Hartley business listing Be the first listing in Hartley Common questionsWhat is the postcode for Hartley?Hartley, SA has the postcode 5255.What state is Hartley in?Hartley is in South Australia (SA).Does postcode 5255 cover more than one suburb?Yes. Postcode 5255 covers 19 localities, so the postcode alone does not identify Hartley. Browse other postcodes in South Australia, or widen the search to every Australian postcode.