Home Postcodes by state NSW 2028 Postcode 2028 2028 is the postcode for Double Bay, NSW. Localities with postcode 2028Double BayNSW Postcode 2028 State or territory New South Wales (NSW) Localities 1 Council area Woollahra Council area based on Australian Bureau of Statistics data (ASGS Edition 3), CC BY 4.0. Postcode 2027 · Postcode 2029