19 CFR § 10.2006 - Certification not required.
(1) A non-commercial importation of a good; or
(b)Exception. If the Center director determines that an importation described in paragraph (a) of this section is part of a series of importations carried out or planned for the purpose of evading compliance with the certification requirements of § 10.2004, the Center director will notify the importer that for that importation the importer must submit to CBP a copy of the certification. The importer must submit such a copy within 30 days from the date of the notice. Failure to timely submit a copy of the certification will result in denial of the claim for preferential tariff treatment.