RO and UV water purifiers, filters and their cartridges.
Water Purifier falls under HSN 8421, in chapter 84 (Machinery and computers).
Home and commercial water purifiers are subheading 842121 and taxed at 18%. Replacement membranes and filter cartridges are parts of 842199. Annual maintenance contracts for purifiers are a service at 18%.
| Code | Description |
|---|---|
| 842121 | Machinery for filtering or purifying water (RO, UV purifiers) |
| 842199 | Parts (filter cartridges, membranes) |
The GST rate on water purifier is 18%.
| GST rate | Within a state | Between states |
|---|---|---|
| 18% | CGST 9% + SGST 9% | IGST 18% |
Compare other goods on the GST rates list.
The number of digits depends on your aggregate turnover in the previous financial year.
| Turnover last year | Digits | Write |
|---|---|---|
| Up to Rs 5 crore | 4 on B2B invoices, optional on B2C | 8421 |
| Above Rs 5 crore | 6 on every invoice | 842121, 842199 |
| Export or import | 8 on the shipping bill or bill of entry | From the Customs Tariff, chapter 84 |
Here is how a line for water purifier looks on a tax invoice within one state: 3 × purifier at Rs 11,500.00 each, taxed at 18%. The figures are an example, not a market price.
| Item | HSN | Qty | Rate (Rs) | Taxable (Rs) | CGST (Rs) | SGST (Rs) | Total (Rs) |
|---|---|---|---|---|---|---|---|
| Water Purifier | 8421 | 3 × purifier | 11,500.00 | 34,500.00 | 3,105.00 | 3,105.00 | 40,710.00 |
Sold to a buyer in another state, the same line carries IGST of Rs 6,210.00 instead of CGST and SGST. Make the full invoice with the GST invoice format: it fills in the tax split, round off and amount in words.
Chapter 84 (Machinery and computers) covers: Engines, pumps, machines, appliances such as ACs and fridges, computers and their parts.
Products often bought, sold or invoiced together with water purifier:
Water Purifier falls under HSN 8421: RO and UV water purifiers, filters and their cartridges. Common 6 digit codes are 842121 for machinery for filtering or purifying water (RO, UV purifiers) and 842199 for parts (filter cartridges, membranes).
18%: CGST 9% plus SGST 9% on a sale within a state, or IGST 18% on a sale between states.
If your aggregate turnover in the previous financial year was up to Rs 5 crore, write the 4 digit code 8421 on B2B invoices (optional on B2C invoices). Above Rs 5 crore, write 6 digits, such as 842121, on every invoice. Shipping bills and bills of entry need the full 8 digit code from the Customs Tariff.
Rates checked on 13 October 2026 against the GST rate notifications in force (GST 2.0 from 22 September 2025). Descriptions are in our own words and are a guide, not a ruling: for a disputed or high value item, check the notification or ask your tax adviser.