Home Postcodes by state SA 5233 Postcode 5233 5233 is the postcode for 3 localities in SA: Forreston, Gumeracha and Warren. Localities with postcode 5233ForrestonSAGumerachaSAWarrenSA Postcode 5233 State or territory South Australia (SA) Localities 3 Council area Adelaide Hills Council area based on Australian Bureau of Statistics data (ASGS Edition 3), CC BY 4.0. Postcode 5232 · Postcode 5234