Code of Federal Regulations Title 19. Customs Duties § 19.102.19 NAFTA preference override

(a) Except in the case of goods covered by paragraph (b) of this section, if a good which is originating within the meaning of § 181.1(q) of this chapter is not determined under § 102.11(a) or (b) or § 102.21 to be a good of a single NAFTA country, the country of origin of such good is the last NAFTA country in which that good underwent production other than minor processing, provided that a Certificate of Origin (see § 181.11 of this chapter) has been completed and signed for the good.

(b) If, under any other provision of this part, the country of origin of a good which is originating within the meaning of § 181.1(q) of this chapter is determined to be the United States and that good has been exported from, and returned to, the United States after having been advanced in value or improved in condition in another NAFTA country, the country of origin of such good for Customs duty purposes is the last NAFTA country in which that good was advanced in value or improved in condition before its return to the United States.