Home Postcodes by state NSW 2020 Postcode 2020 2020 is the postcode for 3 localities in NSW: Mascot, Sydney Domestic Airport and Sydney International Airport. Localities with postcode 2020MascotNSWSydney Domestic AirportNSWSydney International AirportNSW Postcode 2020 State or territory New South Wales (NSW) Localities 3 Council area Bayside Council area based on Australian Bureau of Statistics data (ASGS Edition 3), CC BY 4.0. Postcode 2019 · Postcode 2021