Home Postcode finder TAS Gretna Gretna postcode TAS Gretna is a locality in Tasmania covered by postcode 7140. Postcode 7140 State or territory Tasmania (TAS) Region Tasmania Add a free Gretna business listing Be the first listing in Gretna Common questionsWhat is the postcode for Gretna?Gretna, TAS has the postcode 7140.What state is Gretna in?Gretna is in Tasmania (TAS).Does postcode 7140 cover more than one suburb?Yes. Postcode 7140 covers 48 localities, so the postcode alone does not identify Gretna. Browse other postcodes in Tasmania, or widen the search to every Australian postcode.