Section 143.13 - Documents to be presented with entryThe importer shall in all cases present:
(a) Any bills or statements of cost, or their electronic equivalents, relating to the merchandise which may be in his possession; and(b) A declaration, or its electronic equivalent, that he has no other information as to the value of the articles and is unable to obtain such information or to determine the value of the articles for the purpose of making formal entry thereof.T.D. 73-175, 38 FR 17463, July 2, 1973, as amended by CBP Dec. 15-14, 80 FR 61289, Oct. 13, 2015