law: 21. Periodical payment of tax and filing of returns.
  (1) Tax payable under this Act shall be paid in the manner hereinafter provided at such intervals as may be prescribed.
  (2) Every registered dealer and every other dealer who may be required so to do by the Commissioner by notice served in the prescribed manner shall furnish such returns of turnover by such dates and to such authority as may be prescribed.
  (3) Every registered dealer required to furnish returns under sub-section (2) shall pay into a Government Treasury or the Reserve Bank of India or in such other manner as may be prescribed, the full amount of tax due from him under this Act according to such return, and shall where such payment is made into a Government Treasury or the Reserve Bank of India furnish along with the return a receipt from such Treasury or Bank showing the payment of such amount.
  (4) If any registered dealer discovers any mistake or error in any return furnished by him, he may at any time, before the expiry of three months next following the last date prescribed for furnishing of the return, furnish a revised return, and if the revised return shows a higher amount of tax to be due than was shown in the original return, it shall be accompanied by a receipt showing payment in the manner provided in sub-section (3) of the excess amount.
  (5) Every return under this section shall be signed and verified
  (a) in the case of an individual, by the individual himself, and where the individual is absent from India by the individual concerned or by some person duly authorised by him in this behalf and where the individual is mentally incapacitated from attending to his affairs, by his guardian or by any other person competent to act on his behalf;
  (b) in the case of a Hindu undivided family, by a Karta, and where the Karta is absent from India or is mentally incapacitated from attending to his affairs, by any other adult member of such family;
  (c) in the case of a company or local authority, by the principal officer thereof; (d) in the case of a firm, by any partner thereof, not being a minor;
  (e) in the case of any other association, by any member of the association or the principal officer thereof; and
  (f) in the case of any other person, by that person or by some person competent to act on his behalf.
  (6) For the purposes of sub-section (5) of officer" shall have the meaning assigned to it Act, 1961 (43 of 1961). this section and section 59 the expression "principal under clause (35) of section 2 of the Income-Tax