[Code of Federal Regulations] [Title 19, Volume 2] [Revised as of April 1, 2003] From the U.S. Government Printing Office via GPO Access [CITE: 19CFR181.21] [Page 358] TITLE 19--CUSTOMS DUTIES CHAPTER I--UNITED STATES CUSTOMS SERVICE, DEPARTMENT OF THE TREASURY PART 181--NORTH AMERICAN FREE TRADE AGREEMENT--Table of Contents Subpart C--Import Requirements Sec. 181.21 Filing of claim for preferential tariff treatment upon importation. (a) Declaration. In connection with a claim for preferential tariff treatment for a good under the NAFTA, the U.S. importer shall make a written declaration that the good qualifies for such treatment. The written declaration may be made by including on the entry summary, or equivalent documentation, the symbol ``CA'' for a good of Canada, or the symbol ``MX'' for a good of Mexico, as a prefix to the subheading of the HTSUS under which each qualifying good is classified. Except as otherwise provided in Sec. 181.22 of this part and except in the case of a good to which appendix 6.B. to Annex 300-B of the NAFTA applies (see, however, Sec. 12.132 of this chapter), the declaration shall be based on a complete and properly executed original Certificate of Origin, or copy thereof, which is in the possession of the importer and which covers the good being imported. (b) Corrected declaration. If, after making the declaration required under paragraph (a) of this section or under Sec. 181.32(b)(2) of this part, the U.S. importer has reason to believe that a Certificate of Origin on which a declaration was based contains information that is not correct, the importer shall within 30 calendar days after the date of discovery of the error make a corrected declaration and pay any duties that may be due. A corrected declaration shall be effected by submission of a letter or other written statement to the Customs office where the original declaration was filed.