Home Postcode finder SA Forreston Forreston postcode SA Forreston is a locality in South Australia covered by postcode 5233. Postcode 5233 State or territory South Australia (SA) Region Sa Subs Near 2 Add a free Forreston business listing Be the first listing in Forreston Common questionsWhat is the postcode for Forreston?Forreston, SA has the postcode 5233.What state is Forreston in?Forreston is in South Australia (SA).Does postcode 5233 cover more than one suburb?Yes. Postcode 5233 covers 3 localities, so the postcode alone does not identify Forreston. Browse other postcodes in South Australia, or widen the search to every Australian postcode.