Harmonized System - Structure

Structure

Under the HS Convention, the contracting parties are obliged to base their tariff schedules on the HS nomenclature, although parties set their own rates of duty. The HS is organized into 21 sections and 96 chapters, accompanied with general rules of interpretation and explanatory notes. The system begins by assigning goods to categories of crude and natural products, and from there proceeds to categories with increasing complexity. The codes with the broadest coverage are the first four digits, and are referred to as the heading. The HTS therefore sets forth all the international nomenclature through the 6-digit level and, where needed, contains added subdivisions assigned 2 more digits, for a total of 8 at the tariff-rate line (legal) level. Two final (non-legal) digits are assigned as statistical reporting numbers if warranted, for a total of 10 digits to be listed on entries.

To ensure harmonization, the contracting parties must employ all 4- and 6-digit provisions and the international rules and notes without deviation, but are free to adopt additional subcategories and notes. The two final chapters, 98 and 99, are reserved for national use. Chapter 77 is reserved for future international use only. Chapter 98 comprises special classification provisions, and chapter 99 contains temporary modifications pursuant to a parties' national directive or legislation.