Home Postcodes by state ACT 2604 Postcode 2604 2604 is the postcode for 3 localities in ACT: Causeway, Kingston and Narrabundah. Localities with postcode 2604CausewayACTKingstonACTNarrabundahACT Postcode 2604 State or territory Australian Capital Territory (ACT) Localities 3 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 2603 · Postcode 2605