Home Postcodes by state WA 6240 Postcode 6240 6240 is the postcode for Lowden, WA. Localities with postcode 6240LowdenWA Postcode 6240 State or territory Western Australia (WA) Localities 1 Council area Donnybrook-Balingup Council area based on Australian Bureau of Statistics data (ASGS Edition 3), CC BY 4.0. Postcode 6239 · Postcode 6243