The Harmonized System (HS) is harmonized only to six digits. Beyond that, each country or customs union adds its own subdivisions, duty rates, notes and trade measures, so the same product can carry a different national code, a different duty and different import requirements in India, ASEAN, the EU and the US. For a business shipping to several markets, this affects landed cost, compliance risk and the product data in its systems.
Each country adds its own extensions, to 8, 10 or even 12 digits, for domestic tariff, trade policy and statistical needs. The same item could be duty-free in Singapore, taxed in India, restricted in the EU and subject to additional documentation in the US.
The six-digit standard
The World Customs Organization (WCO) maintains the first six digits: the Harmonized Commodity Description and Coding System, applied through the General Rules for the Interpretation (GRIs), the legal notes and, as guidance, the Explanatory Notes. Under Article 3 of the HS Convention, each contracting party must use all HS headings and subheadings without addition or modification, and may create its own subdivisions only at a level beyond the six-digit code.
Example: HS subheading 8517.12, “Telephones for cellular networks or for other wireless networks”, as it stood before HS 2022.
At six digits, India, the US, the ASEAN members and the EU all identify the product the same way, provided they are applying the same HS edition. Once national digits are added, harmonization stops.
Correction: an earlier version of this article presented 8517.12 as an HS 2022 code. HS 2022 deleted subheading 8517.12 and replaced it with 8517.13 (smartphones) and 8517.14 (other telephones for cellular networks or for other wireless networks), as shown, for example, in South Africa’s HS 2022 tariff amendment. The national codes in the table and example below are the pre-2022 codes and are kept here to show the structure; check the current tariff of each country for today’s codes.
How countries go beyond six digits
| Jurisdiction | Code structure | Example extension (pre-2022) | Purpose |
| India (ITC-HS) | 8 digits | 8517.12.11 | Trade policy, import licensing, customs duty |
| ASEAN (AHTN) | 8 digits | 8517.12.20 | Regional tariff alignment, intra-ASEAN trade |
| EU (CN/TARIC) | 8 digits (CN), 10 digits (TARIC) | 8517.12.0000 | Duty calculation, anti-dumping, quotas |
| US (HTSUS) | 10 digits (8-digit tariff line plus 2-digit statistical suffix) | 8517.12.0050 | Import duties, regulatory controls, statistics |
Each country or region builds on the WCO base but differs in structure, interpretation and application, which produces several tariff outcomes for identical products. Even the six-digit classification can diverge when customs authorities read the same rules differently: the smartwatch ruling comparison shows Canada and the US placing smartwatches in different headings.
Example: one smartphone, four national codes
A smartphone classified in subheading 8517.12 (before HS 2022) shows the divergence. The rates below are the ones given in the first version of this article and have not been rechecked; some are likely out of date. Check each country’s official tariff before relying on them.
- India: 8517.12.11, “Mobile phones”: Basic Customs Duty 10% plus IGST.
- ASEAN (Singapore): 8517.12.20, “Cellular telephones”: 0% MFN rate.
- EU: 8517.12.0000, “Telephones for cellular networks”: 0% duty, but environmental fees apply.
- US: 8517.12.0050, “Cellular telephones”: 0% under the HTSUS, but Section 301 tariffs may apply to goods of Chinese origin.
The same device, with an identical specification, has four national codes, different duty rates and different import documentation requirements. Comparing tariffs across jurisdictions like this is routine work for any company with a multi-country supply chain.
Why national variations exist
Each customs administration designs its national digits around its own policy, trade agreements and statistics:
- India’s ITC(HS) ties the tariff line to import and export policy, licensing and DGFT regulations.
- The ASEAN AHTN gives the region a common 8-digit structure, though members may interpret it differently.
- The EU’s TARIC adds layers for anti-dumping duties, tariff quotas and origin-based preferences.
- The US HTSUS carries additional duties such as Section 301 measures in Chapter 99. Export control classification numbers (ECCNs) are a separate system under the Export Administration Regulations, not part of the HTSUS.
So even when every country follows the same six-digit classification, local adaptation produces different results, which complicates both duty calculation and regulatory compliance in the supply chain.
The risks for multinational companies
These variations go well beyond paperwork. If entities in different countries classify the same product inconsistently, landed cost models and duty forecasts are wrong. Different national codes can lead to different preferential or origin-based rates. Mismatched extensions in ERP and customs systems break import and export data feeds. And a misclassification found in one country can prompt questions in others where the same product is imported.
Compliance teams therefore need the classification to be consistent at the six-digit level and correct at each national level.
Defending a code across jurisdictions
When a code is challenged, the justification has to show the reasoning for both the HS subheading and the national line. A defensible classification file includes:
- The product description and technical specifications.
- The GRIs applied and the relevant Explanatory Notes.
- The Section and Chapter Notes relied on.
- Country-specific legal sources, such as EU CN notes, Indian tariff and ITC(HS) notes, or US rulings.
- A comparison showing how other jurisdictions classify the same item.
The legal basis for each of these is explained in the legal anatomy of HS classification, and the file itself in building an audit-proof HS classification file.
Managing tariff divergence
- Keep one central HS database with the national extensions for each country.
- Map every six-digit code to its 8- and 10-digit national lines.
- Update codes when the WCO amends the HS and when national customs authorities issue notifications. HS 2028 enters into force on 1 January 2028, and national tariffs will change with it; see HS 2028, sector by sector.
- Review the classification logic for high-volume products regularly.
- For dual-use goods, have tariff classifiers and export control classifiers check each other’s work, since the HS code and the ECCN are determined separately.
Technology and expertise
Classification software can suggest codes at the six-digit level. Interpreting the national lines beyond six digits still needs someone who understands each country’s rules and rulings as well as the GRIs, and automation works best when that person checks and directs it.