Home Postcodes by state WA 6112 Postcode 6112 6112 is the postcode for 12 localities in WA: Armadale, Bedfordale, Brookdale, Forrestdale, Harrisdale, Haynes and 6 more. Localities with postcode 6112ArmadaleWABedfordaleWABrookdaleWAForrestdaleWAHarrisdaleWAHaynesWAHilbertWAMount NasuraWAMount RichonWAPiara WatersWASeville GroveWAWungongWA Postcode 6112 State or territory Western Australia (WA) Localities 12 Council area Armadale Council area based on Australian Bureau of Statistics data (ASGS Edition 3), CC BY 4.0. Postcode 6111 · Postcode 6121