Home Postcode finder NSW Holts Flat Holts Flat postcode NSW Holts Flat is a locality in New South Wales covered by postcode 2631. Postcode 2631 State or territory New South Wales (NSW) Region Canberra Add a free Holts Flat business listing Be the first listing in Holts Flat Common questionsWhat is the postcode for Holts Flat?Holts Flat, NSW has the postcode 2631.What state is Holts Flat in?Holts Flat is in New South Wales (NSW).Does postcode 2631 cover more than one suburb?Yes. Postcode 2631 covers 12 localities, so the postcode alone does not identify Holts Flat. Browse other postcodes in New South Wales, or widen the search to every Australian postcode.