Home Postcodes by state WA 6401 Postcode 6401 6401 is the postcode for 18 localities in WA: Buckland, Burlong, Cunjardine, Irishtown, Jennacubbine, Jennapullin and 12 more. Localities with postcode 6401BucklandWABurlongWACunjardineWAIrishtownWAJennacubbineWAJennapullinWAMalabaineWAMeenaarWAMokineWAMuluckineWAMumberkineWAMureskWANorthamWARossmoreWASouthern BrookWASpencers BrookWAThrossellWAWongamineWA Postcode 6401 State or territory Western Australia (WA) Localities 18 Council area Northam; Goomalling Council area based on Australian Bureau of Statistics data (ASGS Edition 3), CC BY 4.0. Postcode 6398 · Postcode 6403