HSN code 3913 is the Customs Tariff heading for natural polymers (for example, alginic acid) and modified natural polymers (for example, hardened proteins, chemical derivatives of natural rubber), not elsewhere specified or included, in primary forms, in Chapter 39 (Plastics and articles thereof). The GST rate is 18%: 9% CGST + 9% SGST within a state, or 18% IGST to another state. Rates are from 9/2025-Central Tax (Rate), as amended, as of 2026-10-21.
GST rate entries for HSN 3913
These are the entries of the current GST rate notifications whose column (2) names heading 3913 or one of its sub-headings or tariff items. The description is the notification's own wording; the goods must match it for the rate to apply.
| HSN scope | Description of goods (notification wording) | GST | Entry |
|---|---|---|---|
| 3901 to 3913 | All goods i.e. polymers; Polyacetals, other polyethers, epoxide resins, polycarbonates, alkyd resins, polyallyl esters, other polyesters; polyamides; Amino-resins, phenolic resins and polyurethanes; silicones; Petroleum resins, coumarone-indene resins, polyterpenes, polysulphides, polysulphones and other products specified in Note 3 to this Chapter, not elsewhere specified or included; Cellulose and its chemical derivatives, not elsewhere specified or included; Natural polymers (for example, alginic acid) and modified natural polymers (for example, hardened proteins, chemical derivatives of natural rubber), not elsewhere specified or included; in primary forms | 18% | 9/2025-CT(R), Schedule II, S. No. 114 |
- 9/2025-CT(R), Schedule II, S. No. 114: One entry shared by 13 headings or chapters (3901, 3902, 3903, 3904, 3905, 3906, 3907, 3908, 3909, 3910, 3911, 3912, 3913); it applies to 3913 in the same way as to the others.
Goods of heading 3913 that do not match any description above fall under the residual entry, Schedule II S. No. 639 ("Goods which are not specified in Schedule I, III, IV, V, VI or VII"), at 18%, unless an "Any Chapter" entry or the nil-rated list of Notification 10/2025-Central Tax (Rate) covers them by description.
Chapter 39 entries that can also apply
These entries name the whole of Chapter 39 in column (2), so they reach every heading of the chapter, including 3913, but only for goods that match their description.
| HSN scope | Description of goods | GST | Entry |
|---|---|---|---|
| 39, 48 | Paper Sacks/Bags and bio-degradable bags | 5% | 9/2025-CT(R), Schedule I, S. No. 319 |
CGST, SGST and IGST split for HSN 3913
The rate notifications fix the central tax (CGST). State tax (SGST, or UTGST in a Union territory without a legislature) is levied at the same rate under the matching state notifications, and IGST on an inter-State supply equals the two together.
| Total GST | CGST | SGST / UTGST | IGST |
|---|---|---|---|
| 5% | 2.5% | 2.5% | 5% |
| 18% | 9% | 9% | 18% |
Worked example: a ₹1,000 sale under HSN 3913
- At 5%: taxable value ₹1,000.00. Within your state, CGST ₹25.00 + SGST ₹25.00 = ₹50.00, invoice total ₹1,050.00. To a buyer in another state, IGST ₹50.00, the same total.
- At 18%: taxable value ₹1,000.00. Within your state, CGST ₹90.00 + SGST ₹90.00 = ₹180.00, invoice total ₹1,180.00. To a buyer in another state, IGST ₹180.00, the same total.
For any other amount, the GST calculator gives the same split, and works backwards from a tax-inclusive price.
How to write HSN 3913 on an invoice
Notification 78/2020-Central Tax sets the number of HSN digits on a tax invoice by the aggregate turnover of the previous financial year. Up to ₹5 crore, print at least 4 digits (3913) on invoices to registered buyers; HSN may be left off invoices to unregistered buyers. Above ₹5 crore, print 6 digits on every tax invoice. Many sellers print the full 8-digit tariff item anyway, because it matches the shipping bill for exports and shows which entry you used.
Charge CGST and SGST when the buyer is in your state and IGST when the place of supply is another state. The invoice also needs your GSTIN, the buyer's GSTIN for B2B sales, the invoice number and date, the quantity, the taxable value and the tax at each rate. The HSN-wise summary in GSTR-1 is built from the same codes, so set the code once per item in your billing software. Make a one-off bill with the free GST invoice generator, or bill every day in FundRaksha Book, which stores the HSN and rate on each item and splits the tax for you.
Other headings in Chapter 39
Chapter 39 of the Customs Tariff is Plastics and articles thereof. This list has 26 of its headings, each with its own page. See all Chapter 39 headings.
- HSN 3901: Polymers of ethylene (18%)
- HSN 3902: Polymers of propylene (18%)
- HSN 3903: Polymers of styrene (18%)
- HSN 3904: Polymers of vinyl chloride (18%)
- HSN 3905: Polymers of vinyl acetate (18%)
- HSN 3906: Acrylic polymers in primary forms (18%)
- HSN 3907: Polyacetals, other polyethers (18%)
- HSN 3908: Polyamides in primary forms (18%)
- HSN 3909: Amino-resins (18%)
- HSN 3910: Silicones in primary forms (18%)
- HSN 3911: Petroleum resins (18%)
- HSN 3912: Cellulose (18%)