This answer explains the formal entry process. Entry of goods must be made by the owner or purchaser of the goods or by a licensed customhouse broker. Right to entry requires the filing of several documents to determine whether the goods can be released from customs custody and the applicable duty to be levied, if any. If the documents are not filed within five days of arrival, the goods may be placed in a warehouse with storage costs to be incurred by the importer. Importers of perishable items may apply for immediate delivery using the Special Entry Permit form 3461.
Inspection is an encompassing step involving appraisal and classification.
During inspection, goods must be valued for duty status, checked for proper country of origin markings, for the shipment of prohibited items, and counted in total. U.S. Customs officials also check the invoice for accuracy. The customs invoice is perhaps the most important document, and should be in English. An invoice should be included with each shipment. The objective of the appraisal is to determine the value of the goods in order to levy tariffs or duties if any.