Home Postcodes by state WA 6237 Postcode 6237 6237 is the postcode for 6 localities in WA: Boyanup, Elgin, Gwindinup, North Boyanup, Stratham and The Plains. Localities with postcode 6237BoyanupWAElginWAGwindinupWANorth BoyanupWAStrathamWAThe PlainsWA Postcode 6237 State or territory Western Australia (WA) Localities 6 Council area Capel Council area based on Australian Bureau of Statistics data (ASGS Edition 3), CC BY 4.0. Postcode 6236 · Postcode 6239