Home Postcodes by state SA 5255 Postcode 5255 5255 is the postcode for 19 localities in SA: Angas Plains, Belvidere, Bletchley, Finniss, Gemmells, Hartley and 13 more. Localities with postcode 5255Angas PlainsSABelvidereSABletchleySAFinnissSAGemmellsSAHartleySAHighland ValleySALake PlainsSALanghorne CreekSAMount ObservationSAMulgundawaSANalpaSARed CreekSASalemSASandergroveSAStrathalbynSATooperangSAWillyarooSAWoodchesterSA Postcode 5255 State or territory South Australia (SA) Localities 19 Council area Alexandrina; Murray Bridge Council area based on Australian Bureau of Statistics data (ASGS Edition 3), CC BY 4.0. Postcode 5254 · Postcode 5256