law: 15. Voluntary registration.
  (1) Any dealer, other than a dealer who deals exclusively in one or more classes of goods specified in the Third Schedule, whose turnover during a year exceeds twenty-fivethousand rupees may, notwithstanding that he may not be liable to pay tax under section 3, apply for registration under this section.
  (2) The provisions of sub-sections (2), (3) and (4) of section 14 shall, as far as may be, apply in relation to registration of dealers under this section.
  (3) Every dealer who has been registered under this section shall, for so long as his registration remains in force, be liable to pay tax under this Act.
  (4) The registration of a dealer under this section shall be in force for a period of not less than three complete years and shall remain in force thereafter unless cancelled under the provisions of this Act.