Power to rectify any error apparent on the face of record.

(1) The authority competent to assess tax under this Act or any appellate authority may, at any time, within three years from the date of any order passed by it, rectify any error apparent on the face of the record: Provided that no such rectification which has the effect of enhancing an assessment or any penalty shall be made unless such authority has given notice to the proprietor and has allowed him a reasonable opportunity of being heard. (2) Where such rectification has the effect of reducing an assessment or penalty, the authority competent to assess tax under this Act shall make any refund which may be due to the proprietor. (3) Where any such rectification has the effect of enhancing an assessment or penalty, the authority competent to assess tax under this Act shall give the proprietor a revised notice of assessment or penalty and, thereupon, the provisions of this Act and the rules made thereunder shall apply as if such notice has been given in the first instance.