Formal entry, as provided for under 19 U.S.C. 1484 in parts 141, 142, and 143 (except for subpart C), of this chapter, is required for all shipments exceeding the monetary limitation for informal entry (see § 128.24 ) and any shipment for which the informal entry procedures may not be used (see § 128.24 ) .
19 C.F.R. §128.25