Home Postcodes by state ACT 2603 Postcode 2603 2603 is the postcode for 4 localities in ACT: Forrest, Griffith, Manuka and Red Hill. Localities with postcode 2603ForrestACTGriffithACTManukaACTRed HillACT Postcode 2603 State or territory Australian Capital Territory (ACT) Localities 4 Council area None: the ACT Government provides local services Council area based on Australian Bureau of Statistics data (ASGS Edition 3), CC BY 4.0. Postcode 2602 · Postcode 2604