Home Postcode finder NSW Mares Run Mares Run postcode NSW Mares Run is a locality in New South Wales covered by postcode 2422. Postcode 2422 State or territory New South Wales (NSW) Region Hunter Add a free Mares Run business listing Be the first listing in Mares Run Common questionsWhat is the postcode for Mares Run?Mares Run, NSW has the postcode 2422.What state is Mares Run in?Mares Run is in New South Wales (NSW).Does postcode 2422 cover more than one suburb?Yes. Postcode 2422 covers 45 localities, so the postcode alone does not identify Mares Run. Browse other postcodes in New South Wales, or widen the search to every Australian postcode.