Home Postcode finder NSW Cornwallis Cornwallis postcode NSW Cornwallis is a locality in New South Wales covered by postcode 2756. Postcode 2756 State or territory New South Wales (NSW) Region Nepean Add a free Cornwallis business listing Be the first listing in Cornwallis Common questionsWhat is the postcode for Cornwallis?Cornwallis, NSW has the postcode 2756.What state is Cornwallis in?Cornwallis is in New South Wales (NSW).Does postcode 2756 cover more than one suburb?Yes. Postcode 2756 covers 28 localities, so the postcode alone does not identify Cornwallis. Browse other postcodes in New South Wales, or widen the search to every Australian postcode.