19 CFR § 10.3007 - Maintenance of records.
(a) General. An importer claiming preferential tariff treatment for a good imported into the United States under § 10.3003(b) based on either the importer's certification or its knowledge must maintain, for a minimum of five years after the date of importation of the good, all records and documents necessary to demonstrate that the good qualifies for preferential tariff treatment under the CTPA. An importer claiming preferential tariff treatment for a good imported into the United States under § 10.3003(b) based on the certification issued by the exporter or producer must maintain, for a minimum of five years after the date of importation of the good, the certification issued by the exporter or producer. These records are in addition to any other records that the importer is required to prepare, maintain, or make available to CBP under part 163 of this chapter.
(b) Method of maintenance. The records and documents referred to in paragraph (a) of this section must be maintained by importers as provided in § 163.5 of this chapter.