Most quotes don’t show tax until the final bill. Here’s how GST is calculated on interior design projects, and how to read it before you sign.
19 Sept 2026
Most interior design quotes in Delhi NCR attract 18% GST, charged on the full value of the project when materials and labour are billed together as one package.
That single number surprises more homeowners than any other line item on an interior design bill. A design firm quotes ₹9 lakh for a 2BHK, the homeowner budgets ₹9 lakh, and then the final invoice reads ₹10.62 lakh once tax is added. The gap is not a hidden charge — it is GST that was never shown clearly in the initial conversation.
This guide explains how GST actually applies to interior design and modular furniture work in India, why the rate can look different depending on how a project is billed, and what to check on your invoice before you sign anything. None of this is a substitute for advice from a chartered accountant on your specific project — treat it as a starting point for asking your designer or contractor better questions.
When a design firm handles both materials and installation as a single package — design, plywood, hardware, labour, and finishing bundled into one quote — this is generally treated as a composite supply centred on a works contract for the interior of your home. Works contract services for immovable property are commonly taxed at 18% GST in India, and most full-scope interior design and modular fit-out packages fall into this bracket.
This is the same 18% figure that shows up across most interior design cost per sq ft quotes once tax is added at the end — which is exactly why it is worth confirming upfront whether a quoted rate is GST-inclusive or GST-exclusive before you compare two designers on price alone.
Where things get more nuanced is when materials and labour are billed separately, or when specific goods (like factory-made modular units bought directly from a brand) are invoiced on their own rather than as part of a composite service. In those cases, the applicable rate depends on how the goods and services are classified individually rather than bundled as one works contract.
A ₹9 lakh GST-inclusive quote and a ₹9 lakh GST-exclusive quote are not the same offer, even though the headline number is identical. On the exclusive quote, the real cost to you is ₹9 lakh plus 18%, or roughly ₹10.62 lakh. On the inclusive quote, ₹9 lakh is the final number you pay.
This is the single most common way homeowners end up comparing two designers unfairly. A firm that quietly quotes GST-exclusive can look ₹1.5–2 lakh cheaper than a competitor on paper for a mid-size project, purely because tax hasn’t been added yet — not because the underlying work is actually less expensive.
Before you compare any two quotes side by side, ask both designers the same direct question: is this number inclusive of GST, or does 18% get added at billing? Get the answer in writing, not verbally, so it is part of the agreement rather than a conversation you remember differently later.
For a composite, single-invoice interior package, GST is calculated on the full taxable value of the contract — design fee, materials, hardware, labour, and supervision combined — not on each line item separately. The basic formula looks like this:
Final Payable Amount = Quoted Project Cost + (Quoted Project Cost × 18%)
So a ₹12 lakh full-home package becomes ₹14.16 lakh once GST is added. A ₹3 lakh modular kitchen becomes ₹3.54 lakh. Whatever the base number, add roughly one-fifth to estimate the real out-of-pocket figure if the quote you were given was GST-exclusive.
This is different from how carpenter labour-only rates are typically billed. When you hire a carpenter directly and supply your own plywood, laminate, and hardware, the carpenter is usually invoicing you for labour alone — and depending on their registration status and turnover, that portion of the bill may be treated differently for tax purposes than a full turnkey works contract. This is one of the reasons a labour-only carpenter quote and a full-service designer quote are not directly comparable without adjusting for what each one actually includes.
A few patterns show up again and again when families in Delhi NCR compare interior design quotes:
Every one of these mistakes is avoidable simply by asking for a written, itemised quote that states the base cost and the GST separately, rather than one bundled number.
A properly issued interior design invoice in India should show these elements clearly, not buried in fine print:
If any of these are missing — especially the GSTIN and the separate tax line — ask for a corrected invoice before making payment. A vendor who is genuinely GST-registered has no reason to avoid showing this information; a vendor who resists usually isn’t registered, which removes any input tax credit option and weakens your position if a dispute comes up later.
Because 18% compounds quickly on larger budgets, it helps to see it applied across a few real project sizes rather than as an abstract percentage:
These ranges are a useful sanity check, not a quote — actual figures for your home will depend on scope, materials, and city. If you want a more accurate starting number for your own space, the full home interior design cost guide breaks down what drives the base number up or down before tax is even added, and the cost calculator can give you a rough estimate to sanity-check against any quote you receive.
Most of the confusion around GST doesn’t come from the tax itself — it comes from designers who quote a number without stating clearly whether tax is included, then add it as a surprise at final billing. We build every Velmore quote as an itemised BOQ with the taxable value and GST shown as separate lines from the first conversation, not the invoice at handover.
If you’re still comparing options and want a number you can trust before you start negotiating, our home interior price calculator gives you a GST-aware estimate based on your actual room count and city, or you can get in touch for a written quote that shows tax the same way your final invoice will.
It helps to separate two things that often get lumped together in a homeowner’s head: paying for a service (design, fabrication, installation) and paying for a product (a ready-made wardrobe, a branded modular kitchen unit, a standalone sofa). Both usually attract GST, but the classification — and sometimes the effective rate — can differ depending on whether you’re buying a finished good off a catalogue or commissioning custom work.
A composite interior design contract, where the designer sources materials, fabricates on-site or in a factory, and installs everything as one service, is typically billed as a single works contract at 18%. A standalone furniture purchase — say, a factory-made wardrobe bought directly from a retailer and delivered flat-pack — is billed as a sale of goods, and the applicable GST rate depends on how that specific product is classified under the goods schedule, which can vary by material and price point.
This distinction matters most when you’re mixing sources for one project — for example, hiring a designer for the living room and buying a ready-made wardrobe separately for a bedroom. Don’t assume the same tax logic applies to both halves of your spend; ask each vendor how their specific invoice is structured rather than applying one rate across your entire renovation budget.
Occasionally a contractor or small carpentry outfit will quote a number with no GST mentioned anywhere — not included, not added later, simply absent. This usually means one of two things: either the vendor’s turnover is genuinely below the GST registration threshold and they are not required to charge it, or they are operating outside the formal tax system entirely and are quietly asking you to look past that.
The first case is common and legitimate, especially with small, local carpentry setups doing labour-only work. The second case is where homeowners run into trouble. An unregistered vendor typically can’t issue a proper tax invoice, which means no GSTIN on record, no formal paper trail if a dispute arises over workmanship, and no easy way to prove what you actually paid if you ever need it for a warranty claim, insurance purposes, or resale documentation on your flat.
If a quote looks unusually low and GST simply isn’t mentioned, ask directly rather than assuming it’s a discount. A short, direct question — "are you GST registered, and will this be on a tax invoice?" — tells you within one reply whether you’re dealing with a formally compliant vendor or taking on risk to save roughly 18% upfront.
GST on interior design work in Delhi NCR is not the confusing part — 18% on a composite works contract is a fairly consistent number across most full-service projects. The confusing part is when it isn’t disclosed until the very end of a negotiation. Ask every designer you’re comparing the same question — inclusive or exclusive — get it in writing, and check that the final invoice shows the GSTIN and tax line separately.
Do that consistently, and GST stops being a budgeting surprise and becomes just another line item you planned for from day one.
Straight answers on tax, invoicing, and what to check before you sign a quote.
Free Tool
No signup needed. Get a realistic budget estimate in under 60 seconds.
Free Interior Cost Calculator →Explore expert interior design articles covering home decor ideas, renovation tips, space planning, material guides, and real project cost breakdowns.
End-to-end home interior solutions including modular kitchens, wardrobes, living room design, space planning, and complete home renovation services tailored to your lifestyle.
