A plumbing contractor's invoice should separate the installation service, coded under SAC 995462 for water plumbing and drain laying, from any pipes, fittings, taps and sanitaryware sold as goods. In a composite contract the entire value is taxed as a works contract at 18%. Goods lines carry HSN 3917 for plastic pipes, 8481 for taps and valves, and 6910 for ceramic sanitaryware, all at 18%. Show pipe material, diameter and pressure class, plus the floor or flat number for apartment jobs.
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Concealed CPVC water supply plumbing for one bathroom incl. pipes and fittings (composite)
995462
6 NOS
14,500.00
87,000.00
18%
UPVC SWR pipe 110 mm, 3 m length
3917
20 NOS
780.00
15,600.00
18%
Ceramic wall-hung WC with seat cover
6910
4 NOS
9,500.00
38,000.00
18%
Single-lever basin mixer, chrome finish
8481
6 NOS
3,200.00
19,200.00
18%
Inspection chamber 450 x 450 mm in brick with CI cover
995462
3 NOS
5,200.00
15,600.00
18%
Taxable value
₹1,75,400.00
GST (CGST + SGST, or IGST if inter-state)
₹31,572.00
Invoice total
₹2,06,972.00
Sample prices are illustrative. Check the GST rate for your exact item or service before billing.
Extra fields a plumbing contractor invoice needs
Pipe material, diameter and class
CPVC, UPVC, PPR and GI pipes differ in price and use. Writing '25 mm CPVC SDR 11' rather than 'pipe' allows the builder to check the specification and supports the correct HSN, 3917 for plastics or 7306 for steel.
Flat or floor reference
On apartment projects plumbing is billed per flat or per floor. Printing the tower and flat number on each line helps the builder track which units are complete and avoids paying twice for the same bathroom.
Pressure test certificate
Concealed lines are pressure tested before tiling. Quoting the test date and pressure on the invoice gives the client proof that the hidden work was checked before it was covered up.
Fixture brand and model
Sanitaryware and CP fittings come in many series. A model number on each line helps the client match the installed fixture to the sample they approved and makes warranty claims easier.
Drainage and chamber details
External drainage, inspection chambers and septic connections are measured in running metres and numbers. Separate lines for these keep them distinct from internal water supply plumbing.
Old fixture removal and debris
Renovation jobs involve dismantling old pipes and fixtures. Listing removal as its own priced line clarifies scope and avoids it being treated as free extra work.
Standard GST invoice fields
Rule 46 of the CGST Rules applies to every tax invoice, including this one:
✓Supplier name, address and GSTIN
✓Consecutive invoice number (max 16 characters, unique for the year)
Fixing pipes inside walls and connecting fixtures is a works contract service under SAC 995462 when you supply material along with labour, and the total is taxed at 18%. Selling a tap or a pipe length across the counter is a sale of goods under its HSN. A plumber who runs a hardware counter and also takes contracts should use separate invoice lines, or separate series, so that GSTR-1 reports the goods HSN and service SAC correctly in the HSN summary table.
Sanitaryware and pipe rates after rationalisation
Notification 9/2025-Central Tax (Rate) lists ceramic sinks, wash basins, WCs and similar sanitary fixtures (6910), plastic baths, sinks and WC seats (3922), plastic tubes and pipes (3917) and taps and valves (8481) in Schedule II at 18%. Hand pumps under 8413 are in the 5% schedule, but power-driven water pumps such as submersible and centrifugal pumps are at 18%. A plumber installing a borewell hand pump on a rural job must bill it separately from electric pumps.
Plumbing work in a residential flat for the builder
If you are a sub-contractor to a builder, your invoice goes to the builder at 18% and the builder may use it as input for its own supply. For apartments sold under the concessional 1% or 5% real-estate rates, the builder cannot take credit, which is why builders often negotiate a lower base price. That does not change the rate on your invoice; a sub-contractor cannot charge 1% or 5% because the builder's apartments carry that rate.
Small plumbers and the registration threshold
An individual plumber offering services only within one state need not register until aggregate turnover exceeds ₹20 lakh (₹10 lakh in special category states). Once registered, every bill above ₹200 to a registered person needs a tax invoice. Unregistered plumbers cannot charge GST or print GST on their bills. If a builder deducts tax or asks for a GSTIN, explain whether you are below the threshold rather than inventing a number.
Common billing mistakes
✕Billing a full bathroom plumbing job as 'labour charges' while the pipes and fittings were in fact supplied by you.
✕Using HSN 3917 for GI or steel pipes, which belong under chapter 73.
✕Charging the builder 1% or 5% because the flats are under a concessional real-estate scheme.
✕Not mentioning the tower and flat number, so the builder cannot reconcile billing with completed units.
✕Bundling a submersible pump with hand pumps at 5% when power-driven pumps are taxed at 18%.
Plumbing contractor GST invoice: FAQ
What SAC code is used for plumbing services?
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Use 995462 for water plumbing and drain laying services. Repairs, alterations and replacement of plumbing installations come under 995469.
What is the GST on sanitaryware?
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Ceramic sanitaryware under HSN 6910 is taxed at 18%. Plastic sanitary items such as baths and WC seats under 3922 are also at 18%.
What HSN code is used for CPVC and PVC pipes?
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Plastic tubes, pipes and hoses with their fittings are classified under HSN 3917 at 18% GST. Steel pipes fall under 7304 or 7306.
Does a plumber need GST registration?
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Registration is required once your aggregate turnover crosses ₹20 lakh for services in most states, or earlier if you make inter-state taxable supplies of goods or sell through an e-commerce operator.
Can I charge GST on a pure repair visit?
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If you are registered, yes. A repair call for a leaking tap is a taxable service at 18% under SAC 995469, and any spare parts you fit are added to the value.