Home Postcode finder SA Highland Valley Highland Valley postcode SA Highland Valley 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 Highland Valley business listing Be the first listing in Highland Valley Common questionsWhat is the postcode for Highland Valley?Highland Valley, SA has the postcode 5255.What state is Highland Valley in?Highland Valley 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 Highland Valley. Browse other postcodes in South Australia, or widen the search to every Australian postcode.