Home Postcode finder NSW Round Corner Round Corner postcode NSW Round Corner is a locality in New South Wales covered by postcode 2158. Postcode 2158 State or territory New South Wales (NSW) Region Seven Hills Add a free Round Corner business listing Be the first listing in Round Corner Common questionsWhat is the postcode for Round Corner?Round Corner, NSW has the postcode 2158.What state is Round Corner in?Round Corner is in New South Wales (NSW).Does postcode 2158 cover more than one suburb?Yes. Postcode 2158 covers 3 localities, so the postcode alone does not identify Round Corner. Browse other postcodes in New South Wales, or widen the search to every Australian postcode.