GST on Under-Construction Property vs Ready-to-Move Flats

Two flats in the same city, priced identically per square foot, can end up costing a buyer very different amounts once tax is added, and the reason has nothing to do with the flat itself. It comes down to one fact: whether a completion certificate had been issued for that unit before you paid for it. That single detail decides whether GST applies to your purchase at all, and if it does, it changes what you owe on top of the agreement value. This guide covers why under-construction and ready-to-move property are treated so differently under GST, what that means for the price a builder quotes you, and what to actually ask before you sign anything, for FY 2026-27.

The Core Distinction: A Construction Service vs a Sale of Immovable Property

GST doesn't tax 'property' as a category. It taxes supplies, meaning goods and services. That distinction is exactly what decides whether your flat purchase attracts GST, and it hinges on timing rather than on what the flat looks like or how it's described in a brochure.

When you book a flat that's still being built and pay the builder before a completion certificate has been issued, or before the building has seen what's legally called first occupation, whichever happens earlier, what you're actually paying for is unfinished work: the builder is still constructing the unit you'll eventually own. Under GST law, this is treated as a supply of construction service, and a service falls squarely within GST's scope. That's why GST applies to an under-construction flat in the first place.

Once a completion certificate has been issued and the entire price for a unit is paid only after that point, the picture changes completely. There's no more construction service being supplied. What's being transferred is a finished, standing structure, and a sale of already-built immovable property, land and buildings, is specifically kept outside GST's scope altogether, under Schedule III of the CGST Act. Not taxed at a lower rate. Not exempt. Outside the scope of what GST can even reach.

This is a structural feature of GST law that has stayed stable since GST began, and it wasn't touched by the GST 2.0 rate rationalisation that reshaped GST's rate slabs from September 2025. GST 2.0 changed rates, not scope. Don't assume that because rates shifted, whether GST applies to a given property transaction shifted too. The completion certificate test is unchanged.

GST on Under-Construction Property: The Rate and the ITC Question

Once you've established that a purchase is a construction service and therefore inside GST's scope, the next question is how much. This is where honesty matters more than a tidy answer: under-construction residential property attracts GST at a specific rate under the current rate structure, but this site's own verified rate data, the GST rate slabs this site maintains and checks against the official GST portal, covers the broad Nil, 5%, 18%, and 40% slab structure introduced by GST 2.0 and doesn't confirm a specific, current, real-estate-specific figure.

That's worth being direct about rather than guessing. Real estate has historically sat at its own dedicated rate outside the standard slab structure, the way gold and silver still do today, rather than simply falling into whichever of the four current slabs sounds closest. A lot of what circulates online about property GST, including once-common figures for 'affordable' versus other housing, predates the September 2025 rate rationalisation and may no longer reflect the current position. Rather than repeat a number that could be stale, confirm the exact current rate, and the input tax credit position that goes with it, against the GST portal or directly against your builder's cost sheet before you rely on any figure, including one quoted to you verbally.

Input tax credit is the mechanism that lets a GST-registered business offset the GST it already paid on its own purchases against the GST it collects on its sales (our guide on input tax credit under GST covers how this works generally). For a builder, that means the GST already paid on cement, steel, other construction materials, and various services that go into building your flat. Whether the builder can claim that credit depends on which rate and ITC combination applies to the project under the current structure, and this site's data doesn't confirm that pairing for real estate specifically. What matters to you as a buyer is the principle, not an unverified specific: a rate that comes without ITC generally pushes the builder's own unrecovered GST cost into the price they quote you, baked in rather than itemised out, the same way it works for a composition-scheme business or a merit-rate service elsewhere under GST. A rate that comes with ITC works the other way, letting the builder net off input costs and, at least in principle, price more competitively. Since this site can't confirm which of these applies to your specific project's rate under the current structure, ask your builder directly which one applies to them, and treat the answer as something to verify rather than assume.

Resale and Ready-to-Move Property: Outside GST, But Not Outside All Tax

If you're buying a flat that already has its completion certificate, whether that's a builder's unsold ready-possession inventory or a resale from an individual owner who's lived in it for years, the same rule applies: this is a sale of immovable property, not a construction service, so GST doesn't apply to the transaction at all. This holds regardless of who's selling. A builder selling a completed, certificate-issued unit for the first time and a homeowner reselling a ten-year-old flat are both, for GST purposes, selling immovable property that sits outside GST's scope.

That doesn't mean the transaction is tax-free. Stamp duty and registration charges still apply, and they apply to under-construction purchases too, not only ready ones. These are separate, state-level costs, set by the state government where the property is located and calculated on the property's value, or the government's circle rate if that's higher, and they're charged regardless of whether GST also applies to the same purchase. Keep these two costs mentally separate: the absence of GST on a ready-to-move flat doesn't mean the absence of transaction tax altogether, and buyers who conflate the two sometimes underbudget for a ready property, assuming it's cheaper across the board when really only one of the two costs has dropped away.

Under-Construction vs Ready-to-Move, Side by Side

The table below lays the two situations side by side. Where a figure isn't confirmed in this site's own rate data, that's stated plainly rather than filled in with a guess.

What to Ask Before You Assume the GST Treatment

A builder's brochure calling a project 'ready to move' is marketing language, not a legal answer about completion certificate status. Before you treat a quoted price as final, or assume you already know whether GST applies, work through this list.

• Ask specifically whether a completion certificate (or occupancy certificate) has been issued for your unit, and ask to see it, rather than accepting 'ready to move' as a substitute for a documented answer.
• If no completion certificate exists yet, confirm whether the price quoted to you includes GST or excludes it. A verbal 'all-inclusive' quote isn't the same as a price that has actually accounted for GST.
• Ask the builder to confirm the applicable GST rate and whether it's being charged with or without input tax credit, and don't treat a phone call or a sales brochure as confirmation. Get it in writing.
• Have the GST treatment, applicable or not, and the rate if it is, written into the sale agreement or allotment letter itself, rather than left as something you assumed from a conversation.
• Budget for stamp duty and registration charges regardless of the GST position. These apply whether or not GST also applies to your purchase.
• If you're buying a resale flat from an individual, don't expect GST to be part of the price at all. If a GST component shows up in that kind of deal, ask why before you pay it.
• If you're funding this purchase partly from the sale of another property and plan to claim a Section 54 or 54F capital gains exemption, check how an under-construction booking is treated for that separate timeline. It isn't the same question as GST, but the two often come up in the same purchase decision. See Section 54 and 54F: How to Save Tax by Reinvesting in a House for how that timeline works.