Almost all shipments crossing international borders including purchases made over the Internet are subject to the assessment of duties and taxes imposed by the importing country's government. The duties and taxes normally must be paid before the goods are released from customs. A Shipment's duty and tax amount may be based on:
- Product value
- Trade agreements
- Country of manufacture
- Use of the product
- The product's Harmonized System (HS) code
Customs officials assess duties and taxes based on the information provided on the Air Waybill, the Commercial Invoice and other relevant documents such as a Certificate of Origin.