Home Postcodes by state NSW 2402 Postcode 2402 2402 is the postcode for 4 localities in NSW: Balfours Peak, Coolatai, Warialda and Warialda Rail. Localities with postcode 2402Balfours PeakNSWCoolataiNSWWarialdaNSWWarialda RailNSW Postcode 2402 State or territory New South Wales (NSW) Localities 4 Council area Mainly Gwydir, partly Inverell; Gwydir Council area based on Australian Bureau of Statistics data (ASGS Edition 3), CC BY 4.0. Postcode 2401 · Postcode 2403