law: Custom Act, 1962 
  28.
  
  Notice for Payment of Duties, Interest Etc. – 
  (1)
  
  When any duty has not been levied or has been short-levied or erroneously
  
  refunded, or when any interest payable has not been paid, part paid or
  
  erroneously refunded, the proper officer may, - 
  (a) in the case of any import made by any individual for his personal use
  
  or by Government or by any educational, research or charitable institution or
  
  hospital, within one year;
  (b) in an other case, within six months, from the relevant date, serve
  
  notice on the person chargeable with the duty or interest which has not been
  
  levied or charged or which has been so short-levied or part paid or to whom the
  
  refund has erroneously been made requiring him to show cause why he should not
  
  pay the amount specified in the notice :
  Provided
  
    that where any duty has not been levied
  
  or has been short-levied or the interest has not been charged or has been part
  
  paid or the duty or interest has been erroneously refunded by reason of
  
  collusion or any wilful miss-statement or suppression of facts by the importer
  
  or the exporter or the agent or employee of the importer or exporter, the
  
  provisions of this sub-section shall have effect as if for the words "one
  
  year" and "six months", the words "five years" were
  
  substituted.
  Explanation
  
  :  Where the service of the notice is
  
  stayed by an order of a court, the period of such stay shall be excluded in
  
  computing the aforesaid period of one year or six months or five years, as the
  
  case may be.
  (2)
  
  The proper officer, after considering the representation, if any made by the
  
  person on whom notice is served under sub-section (1), shall determine the
  
  amount of duty or interest due from such person (not being in excess of the
  
  amount specified in the notice) and thereupon such person shall pay the amount
  
  determined.
  (3)
  
  For the purposes of sub-section (1), the expression "relevant date"
  
  means –
  (a) in a case where duty is not levied, or interest is not charged, the
  
  date on which the proper officer makes an order for the clearance of the goods;
  (b) in a case where duty is provisionally assessed under section 18, the
  
  date of adjustment of duty after the final assessment thereof;
  (c) in a case where duty or interest has been erroneously refunded, the
  
  date of refund;
  (d) in any other case, the date of payment of duty or interest.