Home Postcode finder SA Walker Flat Walker Flat postcode SA Walker Flat 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 Walker Flat business listing Be the first listing in Walker Flat Common questionsWhat is the postcode for Walker Flat?Walker Flat, SA has the postcode 5238.What state is Walker Flat in?Walker Flat 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 Walker Flat. Browse other postcodes in South Australia, or widen the search to every Australian postcode.