Power of revision by Board of Revenue

(1) The Board of Revenue may, at any time, of its own motion or within thirty days from the date of the order of the appellate authority on the application of any party, call for and examine the record of any proceeding pending before or disposed of by the appellate authority and may pass such orders as it deems fit: Provided that no order enhancing the rate of basic tax or the amount of provisional assessment shall be passed without notice to the party who may be affected by the order: Provided further that no order passed on the basis of a reference under section 10 and to the extent covered by the answer to such reference shall be subjected to revision by the Board of Revenue. (2) Where the amount of basic tax or tax under the provisional assessment paid is in excess of the amount due under the order in revision, such excess shall be refunded.