Home Postcodes by state WA 6419 Postcode 6419 6419 is the postcode for Ardath, WA. Localities with postcode 6419ArdathWA Postcode 6419 State or territory Western Australia (WA) Localities 1 Council area Bruce Rock Council area based on Australian Bureau of Statistics data (ASGS Edition 3), CC BY 4.0. Postcode 6418 · Postcode 6420