National Internal Revenue Code (NIRC)
Section 201. Effect of Failure to Stamp Taxable Document. - An instrument, document or paper which is required by law to be stamped and which has been signed, issued, accepted or transferred without being duly stamped, shall not be recorded, nor shall it or any copy thereof or any record of transfer of the same be admitted or used in evidence in any court until the requisite stamp or stamps are affixed thereto and cancelled.