Home Postcodes by state NSW 2403 Postcode 2403 2403 is the postcode for 3 localities in NSW: Delungra, Gragin and Myall Creek. Localities with postcode 2403DelungraNSWGraginNSWMyall CreekNSW Postcode 2403 State or territory New South Wales (NSW) Localities 3 Council area Mainly Inverell, partly Gwydir; Inverell Council area based on Australian Bureau of Statistics data (ASGS Edition 3), CC BY 4.0. Postcode 2402 · Postcode 2404