Home Postcodes by state WA 6477 Postcode 6477 6477 is the postcode for 2 localities in WA: Bencubbin and Welbungin. Localities with postcode 6477BencubbinWAWelbunginWA Postcode 6477 State or territory Western Australia (WA) Localities 2 Council area Mount Marshall Council area based on Australian Bureau of Statistics data (ASGS Edition 3), CC BY 4.0. Postcode 6476 · Postcode 6479