Home Postcodes by state NSW 2223 Postcode 2223 2223 is the postcode for 2 localities in NSW: Mortdale and Oatley. Localities with postcode 2223MortdaleNSWOatleyNSW Postcode 2223 State or territory New South Wales (NSW) Localities 2 Council area Georges River Council area based on Australian Bureau of Statistics data (ASGS Edition 3), CC BY 4.0. Postcode 2222 · Postcode 2224