Home Postcodes by state WA 6011 Postcode 6011 6011 is the postcode for 2 localities in WA: Cottesloe and Peppermint Grove. Localities with postcode 6011CottesloeWAPeppermint GroveWA Postcode 6011 State or territory Western Australia (WA) Localities 2 Council area Cottesloe; Peppermint Grove Council area based on Australian Bureau of Statistics data (ASGS Edition 3), CC BY 4.0. Postcode 6010 · Postcode 6012