Home Postcodes by state QLD 4119 Postcode 4119 4119 is the postcode for Underwood, QLD. Localities with postcode 4119UnderwoodQLD Postcode 4119 State or territory Queensland (QLD) Localities 1 Council area Logan Council area based on Australian Bureau of Statistics data (ASGS Edition 3), CC BY 4.0. Postcode 4118 · Postcode 4120