Home Postcodes by state WA 6355 Postcode 6355 6355 is the postcode for 11 localities in WA: Dunn Rock, East Newdegate, Holt Rock, Lake Biddy, Lake Camm, Little Italy and 5 more. Localities with postcode 6355Dunn RockWAEast NewdegateWAHolt RockWALake BiddyWALake CammWALittle ItalyWAMagentaWAMount SheridanWANewdegateWASouth NewdegateWAVarleyWA Postcode 6355 State or territory Western Australia (WA) Localities 11 Council area Lake Grace; Kulin Council area based on Australian Bureau of Statistics data (ASGS Edition 3), CC BY 4.0. Postcode 6353 · Postcode 6356