Each natural gas company not classified as Class C or Class D prior to January 1, 1984 must file with the Commission by May 18 of the following calendar year, a letter or report of the independent accountant certifying approval, covering the subjects and in the format prescribed in the General Instructions of the applicable Form No. 2 or Form No. 2-A. The letter or report must also identify which, if any, of the examined schedules do not conform to the Commission's requirements and must describe the discrepancies that exist. The Commission will not be bound by the certification of compliance made by an independent accountant under this paragraph.
18 C.F.R. §158.11