law: Indian Stamp Act, 1899 
  32. Certificate by Collector 
  (1) When an instrument brought to the Collector under section 31
  
  is, in his opinion, one of a description chargeable with duty; and- 
  (a) the Collector determines that it is
  
  already fully stamped, or
  (b) the duty determined by the Collector under
  
  section 31, or such a sum as, with the duty already paid in respect of the
  
  instrument, is equal to the duty so determined, has been paid, the Collector
  
  shall certify by endorsement on such instrument that the full duty (stating the
  
  amount) with which it is chargeable has been paid.
  (2) When such instrument is, in his opinion, not chargeable with
  
  duty, the Collector shall certify in manner aforesaid that such instrument is
  
  not so chargeable.
  (3) Any instrument upon which an endorsement has been made under
  
  this section, shall be deemed to be duly stamped or not chargeable with duty,
  
  as the case may be; and, if chargeable with duty, shall be receivable in
  
  evidence or otherwise, and may be acted upon and registered as if it had been
  
  originally duly stamped:
  PROVIDED  that nothing in this section shall authorize
  
  the Collector to endorse- 
  (a) any instrument executed or first executed in 3[India]
  
  and brought to him after the expiration of one month from the date of its
  
  execution or first execution, as the case may be;
  (b) any instrument executed or first executed out of 3[India]
  
  and brought to him after the expiration of three months after it has been first
  
  received in 3[India]; or
  (c) any instrument chargeable 33[with a duty not
  
  exceeding ten naye paise], or any bill of exchange or promissory note, when
  
  brought to him, after the drawing or execution thereof, on paper not duly
  
  stamped.