HTS (or HTSUS)

The Harmonized Tariff Schedule (or Harmonized Tariff Schedule of the United States) Number.  The HTSUS is a hierarchical structure for categorizing all goods in international trade for duty, quota, and statistical purposes. This structure is based upon the international Harmonized Commodity Description and Coding System (HS), administered by the World Customs Organization in Brussels, Belgium.

Almost all countries use tariff classification systems based on the international HS. The HS is defined to the six-digit level, so foreign tariff schedules will be identical with the HTS up the six-digit level but may differ at finer levels of detail. (An exception is when countries implement changes to the HS at different times.