Taxation · Income Tax Liability - Computation and Optimisation

Advance Tax, Interest and Tax Planning Basics

Updated 4 October 2026 · Fact-checked

Advance tax is tax you pay during the tax year, in instalments, when your estimated tax after TDS is ₹10,000 or more. Due dates are 15 June, 15 September, 15 December and 15 March (15%, 45%, 75%, 100% cumulative). Shortfall or delay attracts 1% simple interest per month, and tax planning means choosing the lower-tax regime legally.

Understand Advance Tax, Interest and Tax Planning Basics

Tax is meant to be paid as you earn, not in one lump after the year ends. TDS and TCS do part of this. Advance tax covers the rest. It is the 'pay as you earn' tax on income that has no TDS, or where TDS is too low.

You are liable to pay advance tax if the tax payable for the year, after reducing TDS and TCS, is ₹10,000 or more. This applies to every person: individual, HUF, firm, company. One exception: a resident senior citizen (age 60 or more) with no business or profession income need not pay advance tax. Under the Income-tax Act, 2025 you work with the tax year (for you, 2026-27), and the structure of advance tax is the same as you may have seen earlier: four cumulative instalments.

If you pay too little or too late, interest applies. There are two separate charges. One is for default in paying advance tax at all (you paid less than 90% of the assessed tax). The other is for deferment (you paid, but later than the due dates required). Both are simple interest at 1% per month or part of a month. A part of a month counts as a full month. The two can apply together on the same case, so compute them separately.

Tax planning is the lawful use of the law's choices to reduce tax. It is not evasion (hiding income) and not a sham arrangement. At this level, the main choices are: the new regime (default, lower slab rates, few deductions) versus the old regime (higher rates, many deductions and exemptions), and claiming every eligible deduction. You compare total tax under both and pick the lower, then plan advance tax on that figure.

Key rules to remember

Liability to pay advance tax: Estimated tax payable − TDS/TCS ≥ ₹10,000; Use tax on estimated total income including cess. Below ₹10,000 means no advance tax.
Exempt persons: Resident senior citizen (60 or more) with no business/profession income: not liable; A non-resident senior citizen, or one with business income, is not exempt.
Instalments (other than presumptive): By 15 June: at least 15% | By 15 Sept: at least 45% | By 15 Dec: at least 75% | By 15 March: 100%; Percentages are cumulative, applied to the advance tax payable. Instalment amount = cumulative % × advance tax − already paid.
Presumptive taxpayers: Entire advance tax in one instalment on or before 15 March; For persons opting for the presumptive scheme for business or for specified professions. Check the facts given in the question.
Payment up to 31 March: Advance tax paid by 31 March counts as advance tax of that tax year; Paid after that, it is self-assessment tax, not advance tax.
Interest for default in advance tax: 1% × number of months or part months × (assessed tax − advance tax paid); Applies only if advance tax paid is less than 90% of assessed tax. Period runs from 1 April after the tax year to the date of payment or assessment. Assessed tax is net of TDS/TCS.
Interest for deferment: June and September: 1% × 3 months × shortfall; Shortfall = 15% (June) or 45% (Sept) of tax on returned income − advance tax paid by that date. Charged only if paid is below 12% (June) or 36% (Sept) of that tax.
Interest for deferment: December and March: 1% × 1 month × shortfall; December shortfall is measured against 75%; March shortfall against 100% of tax on returned income. Tax on returned income is net of TDS/TCS.
Relief for sudden income: No deferment interest if shortfall arises from capital gains, lottery-type winnings or similar income arising after the due date, and the tax is paid in the remaining instalments; The tax on such income must be paid in the instalments due after it arose, or by 31 March if none remains.

How to solve Advance Tax, Interest and Tax Planning Basics questions

Use this order for any advance tax, interest or planning question. It keeps the working in the sequence the examiner awards marks.

1Compute total income and tax. If regime choice is asked, work out tax under both regimes and pick the lower. Add cess.
2Deduct TDS and TCS to get the net tax payable. If it is below ₹10,000, or the person is an exempt senior citizen, state that no advance tax is due and stop.
3Check the type of taxpayer. Presumptive business or specified professional pays in one instalment by 15 March. Others pay four cumulative instalments.
4Prepare an instalment table: due date, cumulative %, cumulative amount, amount paid, balance. Round as the question directs.
5For default in advance tax: check whether advance tax paid is at least 90% of assessed tax. If not, compute 1% per month or part month on the shortfall from 1 April following the tax year to the date given.
6For deferment: take the tax on returned income less TDS. Test each instalment against its threshold (12% and 36% for the first two). Charge 3 months for June and Sept, 1 month for Dec and March.
7Apply the exceptions: income arising after a due date, such as capital gains. Remove it from the shortfall if tax is paid in the remaining instalments.
8State the total interest, separate for each section, and give a one-line conclusion.

Quickest way: Table-first method for MCQs and written answers

When to use it: When you have under 8 minutes for a numeric question on advance tax or interest.

MCQ check 1: tax net of TDS under ₹10,000 means no advance tax. This eliminates options quickly.
MCQ check 2: for a resident senior citizen with only salary, pension or interest, the answer is usually 'not liable'. Always look for business income.
MCQ check 3: count months with the month-or-part rule. A payment made on 5 July is 4 months from 1 April. Cumulative percentages are 15, 45, 75, 100.
MCQ check 4: remember deferment months are 3, 3, 1, 1. Options that show 3 months for December are wrong.
Written format: draw a four-row table with date, cumulative %, required, paid, shortfall, months, interest. Each filled row earns step marks even if the total is wrong.
Keep the default interest and deferment interest in two separate lines, with a final total. Write the base used for each, because the bases differ.

Common mistakes in Advance Tax, Interest and Tax Planning Basics

Treating ₹10,000 as the limit on gross tax.
Students read 'tax payable' and forget that TDS and TCS are deducted first.
Fix: Always compute tax, add cess, deduct TDS and TCS, then compare with ₹10,000.
Taking instalment percentages as non-cumulative, such as 15%, 30%, 30%, 25%.
The table is remembered as 15, 45, 75, 100, but applied as separate slabs.
Fix: The percentages are cumulative targets. Each instalment is the target minus what you already paid.
Using 3 months of interest for every deferment shortfall.
Students remember 'three months' from the first two dates and generalise.
Fix: Use 3 months for June and September, 1 month for December and March.
Charging default interest from the due date of the first instalment.
Students mix up the deferment and default periods.
Fix: Default interest runs from 1 April after the tax year, on the shortfall of assessed tax, and only if advance tax paid is below 90%.
Forgetting the 12% and 36% thresholds, and charging deferment interest on any shortfall in June and September.
Students compute against 15% and 45% only.
Fix: For June and September, first test paid against 12% and 36% of tax on returned income. Interest arises only if paid is below that threshold, and then it is charged on the full shortfall against 15% and 45%.
Exempting every senior citizen from advance tax.
The exemption is remembered without its conditions.
Fix: The person must be a resident, aged 60 or above, and have no income from business or profession.

Worked examples

Example 1

Mr. Arun, a resident individual aged 40, has a salary and other income. His tax on estimated total income for tax year 2026-27, including cess, is ₹3,40,000. TDS of ₹1,20,000 will be deducted. He has no business income. Is he liable for advance tax? Give the instalment schedule.

Show the solution

Net tax payable = ₹3,40,000 − ₹1,20,000 = ₹2,20,000.
This is above ₹10,000. He is aged 40, so the senior citizen exemption does not apply. He is liable.
By 15 June 2026: 15% × ₹2,20,000 = ₹33,000. Pay ₹33,000.
By 15 September 2026: 45% × ₹2,20,000 = ₹99,000 cumulative. Pay ₹99,000 − ₹33,000 = ₹66,000.
By 15 December 2026: 75% × ₹2,20,000 = ₹1,65,000 cumulative. Pay ₹1,65,000 − ₹99,000 = ₹66,000.
By 15 March 2027: 100% = ₹2,20,000 cumulative. Pay ₹2,20,000 − ₹1,65,000 = ₹55,000.
Check: ₹33,000 + ₹66,000 + ₹66,000 + ₹55,000 = ₹2,20,000.

Answer: Mr. Arun is liable. Instalments: ₹33,000 by 15 June 2026, ₹66,000 by 15 September 2026, ₹66,000 by 15 December 2026, ₹55,000 by 15 March 2027, total ₹2,20,000.

Example 2

Ms. Rekha, a resident professional (not under the presumptive scheme), has tax on total income of ₹2,00,000 as per her return and as assessed, with no TDS. She paid advance tax of ₹40,000 on 15 September 2026, ₹50,000 on 15 December 2026 and ₹60,000 on 15 March 2027. She paid the balance tax with her return on 31 July 2027. Compute interest for default and for deferment in advance tax.

Show the solution

Total advance tax paid = ₹40,000 + ₹50,000 + ₹60,000 = ₹1,50,000. This is 75% of ₹2,00,000, which is below 90%. So default interest applies.
Default interest: shortfall = ₹2,00,000 − ₹1,50,000 = ₹50,000. Period is 1 April 2027 to 31 July 2027 = 4 months (April, May, June, July). Interest = 1% × 4 × ₹50,000 = ₹2,000.
Deferment, June: required 15% = ₹30,000. Paid by 15 June = ₹0. Threshold 12% = ₹24,000. Paid is below it, so interest applies. Interest = 1% × 3 × ₹30,000 = ₹900.
Deferment, September: required 45% = ₹90,000. Paid by 15 Sept = ₹40,000. Threshold 36% = ₹72,000. Paid is below it. Shortfall = ₹50,000. Interest = 1% × 3 × ₹50,000 = ₹1,500.
Deferment, December: required 75% = ₹1,50,000. Cumulative paid = ₹90,000. Shortfall = ₹60,000. Interest = 1% × 1 × ₹60,000 = ₹600.
Deferment, March: required ₹2,00,000. Cumulative paid = ₹1,50,000. Shortfall = ₹50,000. Interest = 1% × 1 × ₹50,000 = ₹500.
Total deferment interest = ₹900 + ₹1,500 + ₹600 + ₹500 = ₹3,500.
Total of both = ₹2,000 + ₹3,500 = ₹5,500.

Answer: Interest for default in advance tax is ₹2,000 and interest for deferment is ₹3,500, a total of ₹5,500 (excluding any interest for late filing of return).

Exam tips

Examiners usually give the tax figure or a short computation. Do not recompute total income unless asked. Spend your time on the instalment table and interest.
Write the base for each interest line: 'assessed tax less advance tax' for default, 'tax on returned income less TDS' for deferment. This shows the examiner you know the difference.
Read the question for the taxpayer type. Words such as presumptive, senior citizen, resident and business income change the answer completely.
For planning questions, show tax under both regimes in two columns, then state the lower one and the saving. Do not just say which is better.
In MCQs on months, mark the payment date first and count each started month as a full one.

Practice questions from Income Tax Liability - Computation and Optimisation

Advance Tax, Interest and Tax Planning Basics in other exams

The same ground in other exams, if you are preparing for more than one or want another angle on it.

Advance Tax, Interest and Tax Planning Basics: frequently asked questions

What are the advance tax due dates for CA Intermediate?

For taxpayers other than presumptive ones, the dates are 15 June (15%), 15 September (45%), 15 December (75%) and 15 March (100%). The percentages are cumulative. Presumptive taxpayers pay everything by 15 March.

Does the Income-tax Act, 2025 change advance tax rules?

The structure for CA Intermediate is the same: a ₹10,000 threshold, four cumulative instalments and 1% monthly interest for default and deferment. The Act uses the term tax year instead of the older terms. Follow the Act and the ICAI material for exact section numbers.

How do I calculate interest for default in payment of advance tax?

Check whether advance tax paid is below 90% of assessed tax. If yes, charge 1% per month or part of a month on the shortfall, from 1 April after the tax year to the date of payment. Assessed tax is net of TDS and TCS.

Is advance tax interest charged on capital gains that arise late in the year?

Deferment interest is not charged on the shortfall caused by capital gains or similar income arising after an instalment date, provided you pay the tax on it in the remaining instalments or by 31 March. Read the date in the question carefully.

How do I choose between the new and old regime in an exam answer?

Compute total tax under both and compare. The old regime helps when eligible deductions and exemptions are large enough to offset its higher slab rates. Write both computations and state the saving.