Home Postcode finder TAS Northdown Northdown postcode TAS Northdown is a locality in Tasmania covered by postcode 7307. Postcode 7307 State or territory Tasmania (TAS) Region Tasmania Add a free Northdown business listing Be the first listing in Northdown Common questionsWhat is the postcode for Northdown?Northdown, TAS has the postcode 7307.What state is Northdown in?Northdown is in Tasmania (TAS).Does postcode 7307 cover more than one suburb?Yes. Postcode 7307 covers 12 localities, so the postcode alone does not identify Northdown. Browse other postcodes in Tasmania, or widen the search to every Australian postcode.