IT Act 1961: s.234A, 234B, 234C · IT Act 2025: s.423–425 · FY 2026-27 (AY 2027-28)
Advance tax actually paid — cumulative instalments (₹)
This calculator computes interest liability under Sections 234A, 234B, and 234C of the Income Tax Act, 1961 (corresponding to Sections 423–425 of the Income Tax Act, 2025) for FY 2026-27 (AY 2027-28).
Section 234C applies when advance tax instalments paid by the prescribed due dates fall short of the required cumulative percentages (15% / 45% / 75% / 100%). Interest is charged at 1% per month for each instalment period of shortfall. A relaxation applies if 12% or 36% of assessed tax is paid by the first two instalments respectively.
Section 234B applies when total advance tax paid by 31 March is less than 90% of the assessed tax liability. Interest accrues at 1% per month from 1 April of the assessment year until the date of actual payment or filing.
Section 234A applies when the return of income is filed after the due date under Section 139(1). Interest at 1% per month is levied on the unpaid tax amount from the due date to the actual date of filing.
Advance tax is not required if the net tax liability (after TDS/TCS) is less than ₹10,000 (Section 208). Senior citizens without business or professional income are also exempt (Section 207). All amounts are rounded to the nearest ₹100 in accordance with Rule 119A.
Step 1 — Tax liability: Enter your total income tax including health and education cess (4%) for FY 2026-27. This is your estimated or assessed tax before any TDS/advance tax.
Step 2 — TDS/TCS credit: Enter the total TDS deducted by employers, banks, etc. plus any TCS collected during the year. The calculator derives the "assessed tax" (net tax payable) automatically.
Step 3 — Instalment payments: Enter the cumulative advance tax paid by each due date. These are cumulative figures — if you paid ₹30,000 in June and ₹20,000 in September, enter ₹30,000 for Q1 and ₹50,000 for Q2.
Step 4 — Filing date: Enter the actual or expected date of return filing. For Section 234A, this date determines whether late-filing interest applies and for how many months.
Step 5 — Due date: Select the applicable return due date — 31-07-2027 for non-audit cases, 31-10-2027 for tax audit cases under Section 44AB, and 30-11-2027 for transfer pricing cases.
FY 2026-27 instalment due dates and cumulative percentages:
| Instalment | Due Date | Cumulative % Required | 234C Period |
|---|---|---|---|
| 1st | 15 June 2026 | 15% | 3 months |
| 2nd | 15 September 2026 | 45% | 3 months |
| 3rd | 15 December 2026 | 75% | 3 months |
| 4th | 15 March 2027 | 100% | 1 month |
Note: Presumptive income taxpayers under Sections 44AD / 44ADA are required to pay 100% of advance tax in a single instalment by 15 March 2027. Section 234C does not apply to them for earlier instalments.
What is the threshold below which advance tax is not required?
If your net tax liability (total tax minus TDS/TCS) is less than ₹10,000, you are not required to pay advance tax (Section 208 of IT Act 1961 / Section 258 of IT Act 2025). Sections 234B and 234C are not attracted in such cases.
Are senior citizens exempt from advance tax?
Yes. Resident senior citizens (age 60 or above) who do not have income from business or profession are exempt from paying advance tax under Section 207(2). However, they may be liable for interest under Section 234A if they file their return after the due date.
What is the 12% / 36% relaxation under Section 234C?
For the 1st instalment (due 15 June), interest under 234C is not charged if the taxpayer has paid at least 12% of the assessed tax by that date — even though 15% is the notional requirement. Similarly for the 2nd instalment (due 15 September), no interest applies if at least 36% is paid cumulatively. This relaxation is built into this calculator automatically.
Is Section 234B interest charged even if I paid 90% advance tax?
No. Section 234B interest applies only when total advance tax paid by 31 March is less than 90% of the assessed tax. If you have paid 90% or more, no interest under 234B is levied even if there was a shortfall in earlier instalments.
How is interest under Section 234A calculated?
Interest under 234A is charged at 1% per month (or part of a month) on the amount of tax unpaid as on the due date. The period runs from the day after the due date to the actual date of filing. Any part of a month counts as a full month for this purpose.
Can Sections 234A and 234B interest run simultaneously?
Yes. Both can apply simultaneously. Section 234B covers the period from 1 April of the assessment year to the payment date. Section 234A covers the period from the return due date to the filing date. If you file after the due date with unpaid tax, both sections apply — but the amounts are computed separately and added together.
How does this calculator handle Rule 119A rounding?
Under Rule 119A of the Income Tax Rules 1962, the base amount on which interest is calculated is rounded down to the nearest multiple of ₹100. This calculator applies this rounding automatically before computing 1% per month interest on any shortfall amount.