U.S. Adoption of the Harmonized System
U.S. Adoption of the Harmonized System took effect on January 1, 1989, when the Harmonized Tariff Schedule of the United States, enacted by the Omnibus Trade and Competitiveness Act of 1988, replaced the Tariff Schedules of the United States.
What happened and why it matters
Adopting the Harmonized System put U.S. tariffs on the same product classification used by most trading nations, which is why the HS code on a supplier's invoice usually matches the first six digits of the U.S. tariff number. The international system is maintained by the World Customs Organization, and the United States adds 8-digit duty rate lines and 10-digit statistical suffixes. The U.S. International Trade Commission publishes the schedule and Customs and Border Protection enforces it. Every import entry now needs an HTS classification, and the code chosen decides the duty rate, any Section 301 or other added tariffs, and whether special rules apply.