Home Postcode finder NSW Blackmans Flat Blackmans Flat postcode NSW Blackmans Flat is a locality in New South Wales covered by postcode 2790. Postcode 2790 State or territory New South Wales (NSW) Region NSW Country West Add a free Blackmans Flat business listing Be the first listing in Blackmans Flat Common questionsWhat is the postcode for Blackmans Flat?Blackmans Flat, NSW has the postcode 2790.What state is Blackmans Flat in?Blackmans Flat is in New South Wales (NSW).Does postcode 2790 cover more than one suburb?Yes. Postcode 2790 covers 40 localities, so the postcode alone does not identify Blackmans Flat. Browse other postcodes in New South Wales, or widen the search to every Australian postcode.