—Guide
Advance Tax on Capital Gains and One-off Income: How to Avoid Interest
How to handle advance tax when you sell property or shares, receive a large one-off payment, or have income that couldn't be predicted at the start of the year.
Advance tax is easy when income is steady. It gets harder when something unexpected happens mid-year — a property sale, a large share sale, a bonus, or a big one-off contract. Handling it correctly avoids interest. This guide explains how.
Note: this article describes the rules under the Income-tax Act, 1961. The Income-tax Act, 2025 applies from 1 April 2026 (tax year 2026-27), with renumbered provisions and updated forms, so check the current position for later periods.
The Special Rule for Capital Gains
You can't reasonably predict in June a gain you'll make in January. So tax on capital gains, and certain other income like lottery winnings, can be paid in the advance tax instalments remaining after the income arises. If you pay it in those instalments, no deferment interest applies on that part of the tax.
Examples
- A flat sold in August: pay the tax on the gain by the 15 September instalment, or across the September, December and March instalments.
- Shares sold in February: pay the tax on the gain by 15 March.
- A gain in the last fortnight of March, after 15 March: pay it by 31 March as advance tax, to avoid default interest.
Other One-off Income
Other one-off income — like a large bonus not subject to enough TDS, a big professional fee, or a business windfall — doesn't get the same special treatment. Advance tax on it should be paid from the next instalment date, and earlier instalments may attract deferment interest if your estimates were too low.
Watch the Default Interest
Even if you pay on time, if total advance tax falls short of 90% of your final tax, default interest applies from 1 April on the shortfall. Paying the balance before 31 March minimises it.
Reinvestment Exemptions
If you plan to reinvest a capital gain to claim an exemption, you can take that into account when estimating advance tax — but only if you're reasonably sure of completing the reinvestment. If the plan falls through, interest may apply.
Checklist
- Tell your advisor about a sale as soon as it happens.
- Compute the gain and tax promptly.
- Pay in the next instalment.
- Top up by 31 March if needed.
Getting Help
Think Filing computes advance tax on capital gains and one-off income in the right instalment, so interest is avoided.