Home Postcodes by state QLD 4120 Postcode 4120 4120 is the postcode for 2 localities in QLD: Greenslopes and Stones Corner. Localities with postcode 4120GreenslopesQLDStones CornerQLD Postcode 4120 State or territory Queensland (QLD) Localities 2 Council area Brisbane Council area based on Australian Bureau of Statistics data (ASGS Edition 3), CC BY 4.0. Postcode 4119 · Postcode 4121