Home Postcodes by state WA 6391 Postcode 6391 6391 is the postcode for 2 localities in WA: Quindanning and Williams. Postcode 6391 State or territory Western Australia (WA) Localities 2 Council area Boddington; Williams Council area based on Australian Bureau of Statistics data (ASGS Edition 3), CC BY 4.0. Localities with postcode 6391QuindanningWAWilliamsWA Browse postcodes in order← 6390 Bannister · 6392 Bokal →