1. Six digits, then local digits
Every HS code begins with six digits that come from the Harmonized System maintained by the World Customs Organization.
Those six digits are the same in every country that applies the system.
Everything after them belongs to the importing country.
2. What the six digits mean
The chapter
The first two digits. Ninety-seven chapters, grouped into twenty-one sections.
The heading
The first four digits.
The subheading
The first six digits.
3. Where countries extend
China
Ten digits. The seventh and eighth are national subheadings; the last two subdivide further.
The European Union
Eight digits under the Combined Nomenclature, ten under TARIC for certain measures.
The United States
Ten digits under the HTSUS.
ASEAN
Eight digits under the AHTN.
4. Why countries extend
Statistics
Finer categories produce finer trade data.
Regulation
Different categories carry different licensing or inspection requirements.
Tariffs
Even within a six-digit subheading, national rates can diverge by subheading.
5. Which code to use where
Export declaration in China
The Chinese ten-digit code.
Import clearance abroad
The destination country’s code.
Certificate of origin
The destination country’s code, not the Chinese one.
Origin assessment
The destination country’s code, because product-specific rules are drafted against that tariff.
6. The common mistakes
Using six digits on an export declaration, which the system will reject.
Putting the Chinese code on a certificate of origin, which the importing authority cannot map.
Assuming that a shared six-digit prefix means the codes are interchangeable.
7. A working habit
For each major export product, record three codes:
The Chinese ten-digit code.
The code in each main destination market.
The six-digit international code, for research and classification opinions.
8. Closing view
Six digits are the international language. The digits after that are the local dialect.
Once that distinction is clear, the question of why the same product carries different codes stops being confusing.
*This article is based on the Harmonized System maintained by the World Customs Organization. Exporters should confirm current codes with the relevant customs authority.*