Home Postcodes by state NSW 2092 Postcode 2092 2092 is the postcode for Seaforth, NSW. Localities with postcode 2092SeaforthNSW Postcode 2092 State or territory New South Wales (NSW) Localities 1 Council area Northern Beaches Council area based on Australian Bureau of Statistics data (ASGS Edition 3), CC BY 4.0. Postcode 2090 · Postcode 2093