What the relief actually covers
Section 54 applies when you sell a long-term residential house and put the gain into another residential house. It is the gain that has to be reinvested, not the whole sale price — so if you put an amount at least equal to the gain into the new house, the entire long-term gain escapes tax; if you reinvest less, only that part is exempt and the rest is taxed.
The relief is for individuals and HUFs, and an NRI claims it on the same footing as a resident. The new house has to be a residential property, and the asset you sold has to have been held long enough to be long-term. It is the cleanest route for a seller who genuinely wants to move from one home to another rather than cash out.
The windows that decide everything
The exemption lives or dies on timing. You can buy the replacement house in a window that opens one year before the sale and closes two years after it. If instead you are building, the new house must be completed within three years of the sale.
| What you do | Deadline measured from the sale |
|---|---|
| Buy a ready house | One year before, up to two years after |
| Construct a house | Within three years |
A house bought more than a year ahead of the sale, or completed past the three-year construction window, does not qualify — and there is no discretion to stretch the dates. This is why the plan is fixed at the time of sale, not improvised afterwards.
When you haven't bought yet — the CGAS account
Sales and purchases rarely line up neatly, and your tax return falls due long before the two- or three-year windows close. The law bridges this with the Capital Gains Account Scheme. Any part of the gain you have not yet reinvested by the due date for filing your return must be deposited into a CGAS account with a bank — and that deposit counts as reinvestment, holding the exemption open.
You then draw from the CGAS account to pay for the new house within the buy or build window. Whatever is left unused in the account when the window closes becomes taxable in that later year. Missing the CGAS deposit deadline is one of the most common ways the exemption is lost — the gain was reinvestable, but it was sitting in an ordinary account when the return came due.
A worked example: Faisal upgrading in Bengaluru
Faisal, an NRI in Dubai, sells a Bengaluru flat in mid-2026 and makes a long-term gain of ninety lakh. He plans to buy a larger flat but has not found one by the time his return is due.
To hold the exemption, he deposits the ninety-lakh gain into a Capital Gains Account Scheme account before his filing due date. Eight months later he buys a flat for one crore, drawing the ninety lakh from the CGAS account and topping up the rest from his own funds. Because the full gain went into the new house within the two-year window, the entire ninety-lakh gain is exempt under Section 54.
Had he instead found a flat costing only sixty lakh, sixty lakh of the gain would be exempt and the remaining thirty lakh would be taxed as long-term gain. The ₹10 crore cap on counted reinvestment never bites here — it only matters where the new house is itself very large.