Home Postcodes by state SA 5141 Postcode 5141 5141 is the postcode for 2 localities in SA: Horsnell Gully and Summertown. Localities with postcode 5141Horsnell GullySASummertownSA Postcode 5141 State or territory South Australia (SA) Localities 2 Council area Adelaide Hills Council area based on Australian Bureau of Statistics data (ASGS Edition 3), CC BY 4.0. Postcode 5140 · Postcode 5142