What is an HS Code and How to Look It Up Correctly

What is an HS Code?

The HS Code (Harmonized System Code) is an internationally standardized goods classification code issued by the World Customs Organization (WCO) and currently applied by more than 200 countries and territories. When exporting or importing a shipment, the HS code is the “common language” that helps customs authorities in every country understand exactly what the goods are.

The role of the HS code is most evident in three areas:

• Determining duty rates: each HS code is linked to import duty rates, special preferential rates under FTAs, excise tax or environmental protection tax (if applicable).
• Determining regulatory requirements: import licenses, quality inspection, quarantine, conformity announcements, etc. are all regulated by HS code.
• The basis for customs clearance: declaring the wrong HS code is one of the most common reasons a declaration is diverted to another channel, subjected to physical inspection, or even penalized.

The structure of an HS code

The international HS code consists of 6 digits: the first 2 digits are the chapter, the next 2 are the heading, and the last 2 are the subheading. Each country may add further digits for detail. Vietnam uses an 8-digit system in its Export-Import Tariff Schedule.

Example: smartphones carry the HS code 8517.13.00, in which:

• 85 — Chapter 85: electrical machinery and equipment and parts thereof;
• 17 — Heading 85.17: telephone sets;
• 13 — Subheading: smartphones;
• 00 — Detail level under Vietnam’s tariff schedule.

The golden rule: a product has only one correct HS code under the classification rules, even if several codes “look similar”. Which code to choose is the result of applying the rules correctly — not guesswork.

How to look up the correct HS code

Step 1: Describe the goods in real detail

Before opening the tariff schedule, answer these questions: what material is the product made of, how is it constructed, what is its principal function, is it raw material, semi-finished or finished goods? “Wood” alone tells little — roundwood, sawn timber and wooden furniture fall under completely different chapters.

Step 2: Consult the Export-Import Tariff Schedule

Use Vietnam’s current Export-Import Tariff Schedule (built on the WCO HS 2022 nomenclature). Read the chapter and heading titles carefully, and especially the legal notes at the beginning of each chapter — these carry the highest legal weight in classification.

Step 3: Apply the 6 General Rules of Interpretation (GRI)

These are the “compass” of classification, in order of priority:

• GRI 1: classification is determined by the terms of the headings and any relative section or chapter notes;
• GRI 2: incomplete, unassembled or mixed goods are classified as if complete;
• GRI 3: goods classifiable under several headings go to the most specific description, then to the component giving the essential character, and finally to the heading occurring last in numerical order;
• GRI 4: goods that cannot be classified under the above rules go to the heading for the most similar goods;
• GRI 5: packing materials and containers presented with the goods are classified with them;
• GRI 6: classification at subheading level follows the same principles.

Step 4: Cross-check duty rates and policies

Once you have narrowed it down to one or two candidate codes, check the MFN rates, preferential rates under the FTAs you plan to use (such as the EVFTA, CPTPP, RCEP, etc.), and the licensing and specialized inspection requirements attached to each code.

Step 5: Request an advance ruling on classification

For high-value shipments or new products, businesses can apply for an advance ruling on goods classification with the customs authority. The result has legal validity, giving businesses confidence in costing and avoiding disputes at clearance.

Common mistakes when declaring HS codes

• Choosing the code with the lowest duty: deliberately declaring a lower-duty code to “save” costs is fraud and may lead to back taxes and penalties.
• Copying the foreign supplier’s code as-is: the first 6 digits are usually identical, but Vietnam’s 2 detail digits may differ — always cross-check against Vietnam’s tariff schedule.
• Skipping the chapter notes: many products are excluded from the “most similar-looking” chapter right in its notes — reading them carefully avoids misclassification from the start.
• Not updating to the latest tariff: the HS nomenclature is reviewed periodically, and codes may change with each revision.

An HS code is not just a string of digits on a declaration — it is the starting point that determines the duties payable, the documents to prepare, and the clearance speed of the entire shipment. Spending time getting it right from the beginning is always far cheaper than fixing mistakes later.