Home Postcode finder NSW Halloran Halloran postcode NSW Halloran is a locality in New South Wales covered by postcode 2259. Postcode 2259 State or territory New South Wales (NSW) Region Gosford Add a free Halloran business listing Be the first listing in Halloran Common questionsWhat is the postcode for Halloran?Halloran, NSW has the postcode 2259.What state is Halloran in?Halloran is in New South Wales (NSW).Does postcode 2259 cover more than one suburb?Yes. Postcode 2259 covers 42 localities, so the postcode alone does not identify Halloran. Browse other postcodes in New South Wales, or widen the search to every Australian postcode.