Home Postcodes by state VIC 3900 Postcode 3900 3900 is the postcode for 2 localities in VIC: Benambra and Cobberas. Localities with postcode 3900BenambraVICCobberasVIC Postcode 3900 State or territory Victoria (VIC) Localities 2 Council area East Gippsland Council area based on Australian Bureau of Statistics data (ASGS Edition 3), CC BY 4.0. Postcode 3898 · Postcode 3902