Home Postcode finder SA Forster Forster postcode SA Forster is a locality in South Australia covered by postcode 5238. Postcode 5238 State or territory South Australia (SA) Region Sa Subs Near 2 Add a free Forster business listing Be the first listing in Forster Common questionsWhat is the postcode for Forster?Forster, SA has the postcode 5238.What state is Forster in?Forster is in South Australia (SA).Does postcode 5238 cover more than one suburb?Yes. Postcode 5238 covers 31 localities, so the postcode alone does not identify Forster. Browse other postcodes in South Australia, or widen the search to every Australian postcode.