Home Postcode finder QLD Duchess Duchess postcode QLD Duchess is a locality in Queensland covered by postcode 4825. Postcode 4825 State or territory Queensland (QLD) Region North QLD Add a free Duchess business listing Be the first listing in Duchess Common questionsWhat is the postcode for Duchess?Duchess, QLD has the postcode 4825.What state is Duchess in?Duchess is in Queensland (QLD).Does postcode 4825 cover more than one suburb?Yes. Postcode 4825 covers 36 localities, so the postcode alone does not identify Duchess. It also appears in 2 states or territories, so it does not identify a state either. Browse other postcodes in Queensland, or widen the search to every Australian postcode.