Home Postcodes by state WA 6405 Postcode 6405 6405 is the postcode for 4 localities in WA: Greenwoods Valley, Meckering, Quelagetting and Warding East. Localities with postcode 6405Greenwoods ValleyWAMeckeringWAQuelagettingWAWarding EastWA Postcode 6405 State or territory Western Australia (WA) Localities 4 Council area Cunderdin Council area based on Australian Bureau of Statistics data (ASGS Edition 3), CC BY 4.0. Postcode 6403 · Postcode 6407