Home Postcodes by state SA 5074 Postcode 5074 5074 is the postcode for 2 localities in SA: Campbelltown and Newton. Localities with postcode 5074CampbelltownSANewtonSA Postcode 5074 State or territory South Australia (SA) Localities 2 Council area Campbelltown Council area based on Australian Bureau of Statistics data (ASGS Edition 3), CC BY 4.0. Postcode 5073 · Postcode 5075