HSN code 38180010 is the 8-digit tariff item for undefused silicon wafers (chemical elements doped for use in electronics, in the form of discs, wafers or similar forms), under heading 3818 and sub-heading 381800 (Chapter 38). GST is 5% or 18%, depending on what the goods are meant to be used for. Rates as of 2026-10-21.
HSN 38180010 at a glance
| Tariff item (8 digits) | 38180010 |
|---|---|
| Heading (4 digits) | 3818: Chemical elements doped for use in electronics, in the form of discs, wafers or similar forms, chemical compounds doped for use in electronics |
| Sub-heading (6 digits) | 381800: Chemical elements doped for use in electronics, in the form of discs, wafers or similar forms, chemical compounds doped for use in electronics |
| Chapter | 38: Miscellaneous chemical products |
| Description | Undefused silicon wafers (chemical elements doped for use in electronics, in the form of discs, wafers or similar forms) |
| GST rate | 5% or 18%, by description |
The rate for 38180010 depends on what the goods are meant to be used for. 5% under 9/2025-CT(R), Schedule I, S. No. 262 for "Silicon wafers"; 18% under 9/2025-CT(R), Schedule II, S. No. 105 for "Chemical elements doped for use in electronics, in the form of discs, wafers or...".
Rate entries that can apply
The description is the notification's own wording. An entry applies only when the goods match it; for 38180010 the deciding question is what the goods are meant to be used for.
| HSN scope | Description of goods | GST | CGST + SGST | Entry |
|---|---|---|---|---|
| 3818 | Silicon wafers | 5% | 2.5% + 2.5% | 9/2025-CT(R), Schedule I, S. No. 262 |
| 3818 | Chemical elements doped for use in electronics, in the form of discs, wafers or similar forms; chemical compounds doped for use in electronics [other than silicon wafers] | 18% | 9% + 9% | 9/2025-CT(R), Schedule II, S. No. 105 |
Worked example: a ₹1,000 sale under HSN 38180010
Work out which entry your goods fall under first; the tax on a ₹1,000.00 sale then is:
- At 5%: CGST ₹25.00 + SGST ₹25.00 (or IGST ₹50.00), invoice total ₹1,050.00.
- At 18%: CGST ₹90.00 + SGST ₹90.00 (or IGST ₹180.00), invoice total ₹1,180.00.
For other amounts, or to work back from a tax-inclusive price, use the GST calculator.
How many HSN digits to print on the invoice
Notification 78/2020-Central Tax sets the minimum by aggregate turnover in the previous financial year: up to ₹5 crore, at least 4 digits (3818) on tax invoices to registered buyers (optional on B2C invoices); above ₹5 crore, at least 6 digits (381800) on all tax invoices. Exports and imports are declared on the shipping bill or bill of entry under the full 8-digit tariff item (38180010), so most exporters print 8 digits on their GST invoices too.
The HSN-wise summary in GSTR-1 uses the same code, so set it once on the item in your billing software. FundRaksha Book stores the HSN and GST rate on each item, splits CGST, SGST and IGST on every bill, and keeps stock and party ledgers alongside.
Other tariff items under sub-heading 381800
- HSN 38180020: Silicon carbide epitaxial thin film on substrate (5% or 18%)
- HSN 38180030: Gallium nitride epitaxial thin film on substrate (5% or 18%)
See every rate entry for the heading on the HSN 3818 page, or all Chapter 38 headings.
Sources
Codes and descriptions: GSTN HSN master (HSN_SAC.xlsx, sheet HSN_MSTR), GST portal, file dated 13.10.2026, read on 21.10.2026; descriptions were converted from capitals and joined with their heading and sub-heading text. Rates: Rates from Notification 9/2025-Central Tax (Rate), 17.09.2025, as amended by Notification 19/2025-Central Tax (Rate) (from 01.02.2026) and Notification 01/2026-Central Tax (Rate) (from 01.05.2026); nil-rated goods from Notification 10/2025-Central Tax (Rate); bricks from Notification 14/2025-Central Tax (Rate).