Home Postcodes by state QLD 4303 Postcode 4303 4303 is the postcode for 3 localities in QLD: Dinmore, New Chum and Riverview. Localities with postcode 4303DinmoreQLDNew ChumQLDRiverviewQLD Postcode 4303 State or territory Queensland (QLD) Localities 3 Council area Ipswich Council area based on Australian Bureau of Statistics data (ASGS Edition 3), CC BY 4.0. Postcode 4301 · Postcode 4304