Home Postcode finder NSW Mount Arthur Mount Arthur postcode NSW Mount Arthur is a locality in New South Wales covered by postcode 2820. Postcode 2820 State or territory New South Wales (NSW) Region NSW Country West Add a free Mount Arthur business listing Be the first listing in Mount Arthur Common questionsWhat is the postcode for Mount Arthur?Mount Arthur, NSW has the postcode 2820.What state is Mount Arthur in?Mount Arthur is in New South Wales (NSW).Does postcode 2820 cover more than one suburb?Yes. Postcode 2820 covers 25 localities, so the postcode alone does not identify Mount Arthur. Browse other postcodes in New South Wales, or widen the search to every Australian postcode.