HSN codes for chemical exports: what do the digits mean?

An HSN code is the number customs uses to classify a product. The first six digits come from the international Harmonized System and mean the same thing in almost every country. India adds two more digits to make an 8-digit national code, called ITC-HS for trade and used in the customs tariff. When you see a chemical listed with a 6-digit code, it names the international subheading. When you see 8 digits, it names the Indian tariff line inside that subheading.

What is the Harmonized System?

The Harmonized Commodity Description and Coding System, usually shortened to HS, is a product nomenclature maintained by the World Customs Organization. Most countries and customs unions base their tariffs and trade statistics on it, so a product classified in one country lands in the same 6-digit subheading in another.

The WCO revises the HS roughly every five years to reflect new products and trade patterns. The current edition is HS 2022. Each revision can split, merge or renumber subheadings, which is why an old invoice and a new one can show different codes for the same material.

"HSN" stands for Harmonized System of Nomenclature. In India the term is used widely, especially for GST, but it refers to the same HS structure.

How are the digits structured?

The code reads from broad to narrow, two digits at a time.

Chapters group whole families of goods. For the products on this site, three chapters do most of the work:

• Chapter 28 covers inorganic chemicals, such as titanium dioxide (2823) and sodium hydroxide, sold as caustic soda flakes (281511) or liquid caustic soda (281512).
• Chapter 29 covers organic chemicals, such as methanol, ethyl acetate (291531) and toluene (290230).
• Chapter 34 covers soaps and organic surface-active agents, which is where surfactants like LABSA and SLES 70% sit, under heading 3402.

Notice how sodium hydroxide splits at the sixth digit: 281511 is the solid, and 281512 is the aqueous solution. The same chemical can sit in two subheadings depending on its form, so it pays to read the full code rather than the heading alone.

Why do some codes have 6 digits and others 8?

The first six digits are shared internationally. Beyond that, each country is free to add its own digits for its tariff and statistics. India's ITC-HS and its customs tariff use 8 digits. The European Union's Combined Nomenclature also uses 8, and the United States' Harmonized Tariff Schedule uses 10 for statistical reporting.

So a 6-digit code and an 8-digit code are not in conflict. A 6-digit code such as 340239 tells you the internationally recognised subheading. An 8-digit code such as 29051100 tells you that subheading plus India's national split. On a product listing, either is a valid way to identify the goods. If your paperwork needs the full national line, ask for it when you request a quote.

The two extra digits are not always meaningful on their own. In many headings the last two digits are "00", which means India has not split that subheading further. In others, the last digits separate named products from an "other" catch-all, so the national line matters for duty and policy.

Which code goes on which document?

Different documents ask for different levels of detail.

• Export shipping bills from India use the 8-digit ITC-HS code. It links the shipment to India's export policy and to any incentive or restriction on that tariff line.
• GST invoices in India show HSN codes at 4, 6 or 8 digits. As a general rule, suppliers with turnover up to ₹5 crore show 4 digits on B2B invoices and larger suppliers show 6, but India requires the full 8-digit HSN on GST invoices for notified chemicals regardless of turnover (CBIC Notification 90/2020-Central Tax).
• The importing country classifies the goods again under its own tariff. The first six digits normally carry across, and the importer's customs broker adds the national digits for the destination.

Because each country applies its own national digits, the importer is responsible for the final classification at destination. Matching the first six digits on both sides is a good first check that everyone means the same product.

Why did some surfactant codes change?

HS 2022 restructured heading 3402, which covers organic surface-active agents. Before that edition, most anionic surfactants were grouped together under 340211. HS 2022 created separate subheadings:

• 340231 for linear alkylbenzene sulphonic acids and their salts, which includes LABSA.
• 340239 for other anionic surfactants, such as SLES, SLS and AOS.
• 340241 for cationic and 340242 for non-ionic surfactants, such as alcohol ethoxylates.

If a supplier or an older database quotes 340211 or 340213 for these products, it is most likely using a pre-2022 edition. Check which edition the importing country applies before you file.

How do you check a code before ordering?

Start with the chemical identity, not the trade name. A CAS number pins down the substance, and the product's form (solid, solution, paste) and concentration often decide the subheading.

1. Confirm the substance by CAS number and the form you are buying.
2. Find the chapter and heading in the HS nomenclature, then the 6-digit subheading.
3. Look up the national tariff of the importing country for the remaining digits and the duty rate.
4. For anything ambiguous, ask your customs broker. Many customs authorities also offer advance or binding rulings that fix the classification before you ship.

Mixtures and preparations are where classification gets hard. A blend of surfactants, a solvent with additives, or a solution at an unusual concentration may move to a different heading than the pure chemical. Read the chapter notes and the explanatory notes for the heading, because they often settle the question.

What should you take away?

The first six digits are the international language; the rest are local. A 6-digit code on a listing is complete at the international level, and an 8-digit code adds India's national line. Read codes from the chapter down, watch for form and concentration, and check which HS edition the destination applies.

Every product on this site shows the HSN code it is traded under, alongside its CAS number. If you need a code confirmed for your documents, mention it in your quote request.