Calculate Advance Tax explained: this guide covers what it means, who it applies to, the step-by-step process, documents required, fees, due dates and penalties in India — so you can stay compliant with confidence and avoid costly mistakes.
To calculate advance tax: estimate total income for the year, compute tax at the applicable rates, add surcharge and cess, reduce by TDS and TCS, and pay the balance across four dates at cumulative 15%, 45%, 75% and 100%. Under the Income-tax Act, 2025 the computation provision is section 405 and the instalment table is section 408.
The five steps
- Estimate current income for the whole year — all heads, not just the one that is easiest to project.
- Compute tax on that estimate at the rates applicable to the taxpayer and the regime chosen.
- Add surcharge and cess where applicable, to arrive at the gross liability.
- Subtract TDS and TCS deductible or collectible on that income. What remains is the advance tax.
- Apportion across the instalments at 15%, 45%, 75% and 100%, cumulatively, reducing each by what has already been paid.
The computation provision requires advance tax to be arrived at after reducing the tax deductible or collectible at source. A salaried person with an additional income stream who forgets this pays twice on the salary and then waits for a refund. Calculate advance tax on the net figure, not the gross.
Worked example — a professional with mixed income
Assume the following estimate for tax year 2026-27, made in June 2026.
| Item | Amount |
|---|---|
| Professional receipts, net of expenses | Rs 24,00,000 |
| Interest income | Rs 1,60,000 |
| Estimated total income | Rs 25,60,000 |
| Estimated tax, surcharge and cess | Rs 4,80,000 |
| Less: TDS on professional fees and interest | (Rs 2,40,000) |
| Advance tax payable | Rs 2,40,000 |
Now apply the instalment percentages to Rs 2,40,000 — the net figure, not Rs 4,80,000.
| Due date | Cumulative | Required to date | Payable now |
|---|---|---|---|
| 15 June 2026 | 15% | Rs 36,000 | Rs 36,000 |
| 15 September 2026 | 45% | Rs 1,08,000 | Rs 72,000 |
| 15 December 2026 | 75% | Rs 1,80,000 | Rs 72,000 |
| 15 March 2027 | 100% | Rs 2,40,000 | Rs 60,000 |
Re-estimating during the year
An estimate made in June is a forecast, and the year rarely cooperates. The design of the instalment system handles this: because the percentages are cumulative, you re-calculate advance tax at each date on the revised annual figure and pay the cumulative percentage of it, less what you have already paid.
Suppose the professional above wins a large engagement and revises the annual advance tax to Rs 3,60,000 by December. The December instalment is 75% of Rs 3,60,000 = Rs 2,70,000, less Rs 1,08,000 already paid = Rs 1,62,000. There is no separate catch-up mechanism to operate; the cumulative structure is the catch-up mechanism.
If the year turns out worse than estimated, the cumulative requirement at the next date may already have been met, so nothing is payable. What has been overpaid is recovered through the return, not by paying less than zero at an instalment date.
The tolerances to calculate against
Perfect estimation is not required, and the deferment provision says so. Section 425(2) provides that no interest arises where at least 12% of the tax due on returned income was paid by 15 June, and at least 36% by 15 September.
That is a genuine planning tool. When you calculate advance tax in June for a year whose income is uncertain, aiming at 15% of a defensible estimate and checking it against the 12% floor is more useful than aiming at a precise number you do not have.
The year-end test that runs separately
Everything above concerns the instalment dates. There is a second, independent test: interest under section 424 applies where the total advance tax paid is less than 90% of assessed tax.
So the final check when you calculate advance tax for March is not "have I paid 100% of my estimate" but "will what I have paid be at least 90% of what the assessment turns out to be". Where an estimate has been conservative all year, March is the point to true it up.
Income that does not have to be estimated in advance
Capital gains and first-time business income receive relief from deferment interest, because neither can honestly be forecast at the start of the year. The relief generally requires the tax on that income to be paid in the remaining instalments once it arises — so a gain in October is dealt with in the December and March instalments, not retrospectively in June's.
Estimating each head — what actually goes wrong
Most errors when people calculate advance tax are not arithmetic. They are omissions at step 1, and they cluster in predictable places.
| Head | What is commonly missed |
|---|---|
| Salary | Nothing usually — the employer's TDS covers it. But a mid-year job change means two employers each computing on their own portion, and the combined liability can exceed the sum of the two deductions. |
| House property | Rent estimated at the current tenant's figure when the lease ends mid-year; and interest deduction claimed at the full figure when the loan is being repaid down. |
| Business or profession | Projecting the whole year off the first quarter. It is the single largest source of a March shortfall. |
| Capital gains | Not omitted so much as mistimed — see the relief below. |
| Other sources | Interest accrued but not yet credited on cumulative deposits, and dividend, which now carries TDS but is taxable at slab rates that often exceed it. |
TDS on dividend and on bank interest is deducted at a flat rate. A taxpayer in a higher slab has a genuine balance to pay on that income even though tax was deducted, and it is invisible unless you calculate advance tax on the gross figure and then credit the TDS. Reading only the net credit in Form 26AS hides it.
Regime choice affects the estimate
The tax computed at step 2 depends on which regime the taxpayer will be in for the year, and that choice changes the deductions available. Where the decision is genuinely open — for a taxpayer whose deduction profile is close to the crossover — estimate under the regime you expect to actually use, and revisit it at the December instalment when the year's investment and expenditure position is clearer.
What you should not do is calculate advance tax under one regime, pay accordingly, and file under the other. If the filed regime produces a higher liability, the shortfall is measured against the filed figure, and the earlier instalments are judged against it too.
Presumptive taxpayers
A taxpayer declaring under the presumptive provision does not calculate advance tax across four dates at all. The whole amount is payable in a single instalment on or before 15 March. The computation itself is simpler too, since income is a prescribed percentage of turnover rather than an actual-profit estimate.
Checklist
- Estimate every head of income, not only the predictable one.
- Reduce by TDS and TCS before applying the instalment percentages.
- Apply 15%, 45%, 75% and 100% cumulatively, netting off earlier payments.
- Re-estimate at each date rather than sticking to a June forecast.
- Check the 12% and 36% tolerances when the estimate is genuinely uncertain.
- True up in March against the 90% of assessed tax test.
- Pay tax on a mid-year capital gain in the remaining instalments to keep the relief.
This is an explanatory guide, not tax advice. Rates, surcharge and thresholds change with the annual Finance Act and are not reproduced here — apply the rates in force for the year you are computing.