Home Postcodes by state SA 5309 Postcode 5309 5309 is the postcode for 4 localities in SA: Borrika, Halidon, Mindarie and Sandalwood. Localities with postcode 5309BorrikaSAHalidonSAMindarieSASandalwoodSA Postcode 5309 State or territory South Australia (SA) Localities 4 Council area Karoonda East Murray Council area based on Australian Bureau of Statistics data (ASGS Edition 3), CC BY 4.0. Postcode 5308 · Postcode 5310