Advance ruling void ab initio when obtained by fraud or suppression, making the statute apply as if no ruling existed. Advance rulings may be declared void ab initio if obtained by fraud, suppression of material facts, or misrepresentation; the Authority or Appellate Authority may order that all provisions of the Act apply to the applicant as if the ruling had never been made, excluding the period between the ruling and the annulment order, provided the applicant has been given an opportunity of being heard, and a copy of the order is sent to the applicant and prescribed officers.