Interest Calculator u/s 234A, 234B, 234C and 220(2)
Check the interest in a 143(1) intimation or demand notice line by line. Enter the year, dates and taxes paid; the calculator applies Rule 119A rounding and shows each month. It runs in your browser: nothing you type is sent to us.
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1Year and dates
2Tax and credits (Rs)
3Taxes paid
What the CPC commonly gets wrong
- Self-assessment tax paid on or before the due date ignored in 234A (CBDT Circular 2/2015 says it reduces the base).
- 234B charged on the full shortfall up to the 143(1) date, without giving effect to self-assessment tax paid earlier.
- 234C recomputed on assessed income instead of returned income.
- TDS that appears in Form 26AS but was not credited, inflating every base.
If the figure in your intimation differs from this one, the difference is usually one of these. A rectification under s.154 or a reply to the 143(1)(a) proposal is the usual route.
Frequently asked questions
How is interest u/s 234A calculated?
At 1% for every month or part of a month from the day after the due date to the date of filing, on the tax on total income less TDS, TCS, reliefs, advance tax and self-assessment tax paid on or before the due date. The amount is rounded down to a multiple of Rs 100 (Rule 119A).
When does 234B interest apply?
When advance tax paid is less than 90% of the assessed tax (tax on total income less TDS/TCS and reliefs) and the assessed tax is Rs 10,000 or more. Interest runs at 1% a month from 1 April of the assessment year to the date of determination, on the shortfall; self-assessment tax reduces the shortfall from the following month.
What is the 12% and 36% rule in 234C?
No 234C interest is charged for the June instalment if at least 12% of the tax was paid by 15 June, or for the September instalment if at least 36% was paid by 15 September. If the cushion is missed, interest is on the shortfall against the full 15% or 45%.
Does a part of a month count as a full month?
Yes. Rule 119A(b) treats a part of a month as a full month where interest is charged for every month or part of a month, so a return filed one day late attracts one full month of 234A interest.
What are the sections for interest under the Income-tax Act, 2025?
Section 423 (late return, was 234A), Section 424 (advance tax default, was 234B) and Section 425 (deferment of advance tax, was 234C), for tax year 2026-27 onwards. The computation is the same.
How is interest u/s 220(2) on a demand calculated?
At 1% for every month or part of a month from the day after the 30-day payment period (s.220(1)) to the date of payment, on the amount unpaid, rounded down to Rs 100.
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