19 C.F.R. § 181.71
Except where a Certificate of Origin either is not submitted when requested under § 181.22(b) of this part or is not acceptable and a corrected Certificate is not submitted or accepted as provided in § 181.22(c) of this part and except as otherwise provided in § 181.23 of this part and except in the case of a pattern of conduct provided for in § 181.76(c) of this part, Customs shall deny preferential tariff treatment on an imported good, or shall deny a post-importation claim for a refund filed under subpart D of this part, only after initiation of an origin verification under § 181.72(a) of this part which results in a determination that the imported good does not qualify as an originating good or should not be accorded such treatment for any other reason as specifically provided for elsewhere in this part.
19 C.F.R. §181.71