Home Postcodes by state ACT 2905 Postcode 2905 2905 is the postcode for 7 localities in ACT: Bonython, Calwell, Chisholm, Gilmore, Isabella Plains, Richardson and 1 more. Localities with postcode 2905BonythonACTCalwellACTChisholmACTGilmoreACTIsabella PlainsACTRichardsonACTTheodoreACT Postcode 2905 State or territory Australian Capital Territory (ACT) Localities 7 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 2904 · Postcode 2906