Home Postcodes by state WA 6126 Postcode 6126 6126 is the postcode for Keysbrook, WA. Localities with postcode 6126KeysbrookWA Postcode 6126 State or territory Western Australia (WA) Localities 1 Council area Mainly Serpentine-Jarrahdale, partly Murray Council area based on Australian Bureau of Statistics data (ASGS Edition 3), CC BY 4.0. Postcode 6125 · Postcode 6147