Tariff Codes, as they're often called, are the Harmonized System Codes, or HS Codes, used by the International Trade Commission (ITC) to classify all outgoing and incoming shipments. Tariff Codes are relevant for ecommerce companies and others shipping in that they are required for each International shipment. The USPS, FedEx, UPS, DHL, and other carriers require that you classify each parcel's item with a Tariff Code, or HS Code as they're known. These are just one of the many parameters required on Customs Forms.
This is just one piece on automating your International shipments. The EasyPost API can help you automate this, as well as the rest of the Customs Forms, rating, purchasing as more. Our Shipping API provides to the following from FedEx, UPS, USPS, DHL, and more: