20. Amendment and Cancellation of Certificate of Registration.- (1) The prescribed authority may, after considering such information as may be furnished by the dealer under section 23 or as may be otherwise received by the said authority, amend the certificate of registration of the dealer in respect of whom the information has been furnished or received. (2) When — (a) any registered dealer discontinues or entirely transfers his business to other persons; or (b) the liability of a registered dealer to pay tax under this Act has ceased, the dealer shall, forthwith, surrender his certificate of registration in the manner prescribed to the prescribed authority and the said authority shall cancel the certificate of registration in the manner prescribed: Provided that, in a case covered by clause (a), the registration certificate shall be deemed to be inoperative with effect from the date of discontinuance or transfer of the business and, in a case covered by clause (b), with effect from the date on which the dealer’s liability to pay tax has ceased. | 