Water Tank HSN Code for GST Filing
Water tanks are used in homes, farms, factories and commercial buildings for storage of drinking water and process water. Traders and manufacturers supply plastic tanks, PVC tanks and metal tanks in many capacities and designs.
For correct GST billing, businesses must know the water tank HSN code, understand how plastic and metal tanks are grouped in the tariff and see how the present slabs of 5%, 18% and 40% after 22 September 2025 apply to these storage products.
How Are Plastic and PVC Water Tanks Classified Under HSN Code?
Under GST, most plastic and PVC water tanks are placed in the family for builders ware of plastics that covers reservoirs, tanks and similar containers. This family usually applies to polymer tanks used for fixed storage in buildings and industrial units.
These tanks are generally made from polyethylene, PVC or similar plastic material and are moulded in cylindrical, rectangular or loft shapes. Even though designs and brand names differ, they normally continue in the same plastic tank HSN family.
Key Water Tank HSN Codes with Indicative GST Treatment after 22 September 2025
| HSN Code | Product Description | Product Type or Variant | GST Rate |
|---|---|---|---|
| 3925 | Plastic and PVC water tanks | Household and industrial polymer tanks for water storage | 18% |
| 3925 | Loft and overhead tanks | Rectangular and special shape plastic tanks fixed in buildings | 18% |
| 7309 | Steel and metal tanks | Large metal tanks for water and other liquids | 18% |
Why Do Water Tanks Have Different HSN Codes for GST?
Water tanks can be made from plastic, fibre, concrete or metal. Plastic and PVC tanks are usually classified as plastic builders ware, while large steel or iron tanks used in industry may fall in the family for tanks and similar containers of iron or steel.
The material, design and use of the tank influence which chapter of the tariff applies. For example, a standard polymer overhead tank for home use will usually follow the plastic builders ware heading, while a heavy steel tank supplied with machinery may follow the metal tank heading.
What is the GST Rate for Plastic, PVC and Other Water Tanks?
In the present three slab GST structure, plastic and PVC water tanks commonly fall in the 18% slab as regular goods. This applies to overhead tanks, loft tanks and similar plastic containers used for storage of water.
Metal tanks that are supplied as separate goods also generally attract 18% when they are classified as tanks and similar containers. The slab may vary if a specific notification provides a concession for a particular type of storage tank, so it is important to watch for such changes.
When tanks are supplied as part of a composite works contract such as a full plumbing installation or plant erection job, the overall contract may be taxed as a service instead of separate goods. In that case, the tank value is built into the works contract rate.
How to Ensure Correct Water Tank HSN Code for GST Filing?
To use the correct water tank HSN code, first identify the material of the tank and whether it is supplied as a stand alone product or as part of a larger installation. Match the tank with the tariff heading that best describes its material and use.
Create separate item masters for plastic tanks, metal tanks and any special storage vessels and assign each item its correct HSN code and GST rate. Use these details on all purchase and sales invoices so that HSN wise data in GSTR one matches your books.
If you sell tanks along with fittings, pipes and installation services, clearly split the goods and services where required or treat the supply as a composite works contract as per the law. This helps avoid confusion during GST audits and assessments.
Conclusion
Water tank HSN code classification places plastic and PVC tanks mainly in the builders ware of plastics family and metal tanks in the tanks of iron or steel family. Under the present GST slab structure after 22 September 2025, these storage products usually fall in the 18% slab as standard goods.
By correctly identifying the tank material, mapping it to the right HSN code and slab, storing these details in the item master and using them on all invoices, traders and contractors can issue correct bills, support proper input tax credit and reduce the risk of disputes in GST returns.
I am a chartered accountant with over 14 years of experience. I understand income tax, GST, and balancing financial records. I analyze financial statements and tax codes effectively. However, I also have a passion for writing, which is different from working with numbers. Recently, I started writing articles and blog posts. My goal is to make finance easier for everyday people to understand.
Frequently Asked Questions
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What is the HSN code for water tanks?
Plastic and PVC water tanks for storage in homes and buildings are usually classified in the builders ware of plastics family that covers reservoirs, tanks and similar containers.
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How do PVC water tanks differ in classification for GST?
PVC tanks are generally treated in the same plastic builders ware family as other polymer water tanks. The difference lies in the product description and brand rather than the main HSN family.
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What is the GST rate for plastic and PVC water tanks?
Plastic and PVC water tanks normally attract 18% as standard goods under the present three slab GST structure unless a specific notification grants a different rate for a special tank type.
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Are there specific HSN codes for different tank materials?
Yes, plastic tanks and metal tanks usually follow different chapters. Plastic tanks fall under plastic builders ware while steel tanks often follow the family for tanks and similar containers of iron or steel.
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How do I file water tank HSN codes correctly for GST returns?
Assign the correct HSN and GST rate to each tank item in your software, use these details on invoices for all outward supplies and allow the software to generate accurate HSN wise summaries for GSTR one.