11.4. Scope of the HS and national subdivision

11. Structure of a chapter – Headings, subheadings and the dash system

Item	Detail
Total headings & subheadings	Approximately 5,000.
Mandatory use	Contracting Parties are required to use all headings and subheadings, subject to the conditions in Article 4.
Exception	Heading 27.16 is an optional heading.
Authority to amend	Only the Harmonized System Committee can make amendments.

In addition to having the HS structure as a base, Contracting Parties may also have domestic subdivisions in their national tariff document. Members that opt to do so must ensure their national structures do not interfere with the HS structure. They must not interfere with or change the scope of the first six figures and their accompanying product descriptions, even if there is no subdivision at the 5- or 6-figure level.

Example:

Heading 09.03, which relates to mate (a traditional South American plant (Ilex paraguariensis) used to make a caffeinated infusion similar to tea), is not further subdivided. If a Contracting Party wished to subdivide the heading, the classification number within their national structure would be 0903.00.[XX], with the ‘XX’ signifying the national eight-digit subheading structure.