The General Rules of Interpretation (GRI) are the six legally binding principles that determine how goods are classified under the Harmonized System. They are applied in strict numerical order — you must rule out GRI 1 before moving to GRI 2, and so on.
- GRI 1 — Classification is determined by the terms of the headings and any relative section or chapter notes. This is the starting point for over 90% of classifications.
- GRI 2(a) — Incomplete or unfinished articles are classified as the complete article if they have the "essential character" of the finished good.
- GRI 2(b) — Mixtures and combinations of materials are classified by reference to GRI 3.
- GRI 3(a) — When goods could fall under multiple headings, the most specific description prevails.
- GRI 3(b) — If specificity doesn't resolve the conflict, classify by the component that gives the article its essential character.
- GRI 3(c) — If essential character can't be determined, classify under the heading that appears last in numerical order.
- GRI 4 — Goods that can't be classified by GRI 1–3 are classified under the heading most akin to them.
- GRI 5 — Special rules for cases, containers, and packing materials.
- GRI 6 — The same principles apply when comparing subheadings within a heading.
In addition, the U.S. has its own Additional U.S. Rules of Interpretation that govern the 8-digit and 10-digit levels.