Interest 234A/B/C
Use this AY 2026-27 calculator as a planning aid. Enter the relevant Indian tax details, review the estimate, and verify final filing decisions against current rules.
What this calculator does
This page helps you estimate the likely result for Interest Calculator (234A, 234B, 234C) from the details entered in the calculator below. Treat the output as a planning estimate, not as a substitute for the final filing computation.
Inputs explained
- Total Tax Liability: Use the figure relevant to your case and keep the unit consistent with the form.
- TDS/TCS Deducted: Use the figure relevant to your case and keep the unit consistent with the form.
- Advance Tax Paid: Use the figure relevant to your case and keep the unit consistent with the form.
- Self Assessment Tax: Use the figure relevant to your case and keep the unit consistent with the form.
- ITR Due Date: Use the figure relevant to your case and keep the unit consistent with the form.
How it works / Method
The calculator uses the values you enter, applies the relevant rule logic for this topic, and updates the result summary immediately after calculation.
Formula or calculation logic
Calculate Interest
Interest Calculation
Enter details to calculate interest.
Step-by-step example
- Enter a realistic value for Total Tax Liability.
- Enter a realistic value for TDS/TCS Deducted.
- Enter a realistic value for Advance Tax Paid.
- Click the calculate button and review the Interest Calculation panel.
Use cases
- Review the likely tax impact before filing or payment.
- Check how changing one input affects the estimate.
- Prepare a cleaner draft working before using the official portal.
Assumptions & limitations
- Results are estimates only and should be checked against the correct FY and AY rules.
- This page does not validate every exemption condition, document requirement, or edge case.
- Verify the latest filing rules before submitting returns, proofs, or tax payments.
Sources & references
Interest Under Section 234
Section 234A - Late Filing
Section 234B - Non-payment of Advance Tax
Section 234C - Deferment of Advance Tax
Section 234A Interest Calculator
Use income tax interest 234a 234b 234c calculator, interest 234 a b c calculator, income tax section 234 abc calculator, or income tax calculator 234 a b c when you need one place for late filing and advance-tax interest. Section 234A interest is generally 1% per month or part month on unpaid tax from the return due date to the filing date.
Section 234B Interest
For a 234b calculator or 234b and 234c interest calculation, Section 234B generally applies at 1% per month when advance tax paid is less than 90% of assessed tax. It is different from 234 c interest calculation, which looks at whether instalments were paid on time.
Section 234C Interest and Advance Tax Instalments
For 234c calculator for fy20-21, 234 c calculator from 234b, advance tax calculator ay 2026-27 with 234abc, and calculate interest 234, use the instalment schedule first.
| Due date | Cumulative advance tax target |
|---|---|
| 15 June | At least 15% |
| 15 September | At least 45% |
| 15 December | At least 75% |
| 15 March | 100% |
Use interest under section 234 calculator online as an estimate only, because relief, TDS, self-assessment tax, and special income can change the final result. The same working notes also cover 234 b and c interest calculator, interest calculator under section 234 abc, 234a interest calculation, and 234 a b c interest calculator ay 2024 25 searches.
FAQs
Section 234A applies when you file your ITR after the due date under Section 139(1), typically 31 July for individuals or 31 October for those needing audit. Interest is 1% per month or part of a month on the unpaid tax liability (after TDS, advance tax and self-assessment paid before due date), running from the day after due date until the date you actually file. Tax of Rs 50,000 unpaid as on due date 31 July, ITR filed on 12 November = 4 months (August, September, October, November). Interest = 50,000 × 1% × 4 = Rs 2,000. If self-assessment tax is paid earlier, 234A stops on that date.
234C penalises shortfalls within the four advance-tax instalments (15 June, 15 September, 15 December, 15 March), charged at 1% per month for 3 months on each instalment shortfall, except the last which is for one month. So if you missed the September deadline by Rs 30,000, interest is Rs 30,000 × 1% × 3 = Rs 900. 234B kicks in only if at the end of the financial year (31 March), less than 90% of total tax is paid through advance tax and TDS. It runs at 1% per month from 1 April until you actually pay, on the assessed-tax shortfall. Both can apply simultaneously.
All three are charged at 1% per month or part of a month, treated as a full month even if you're a single day into it. So delaying payment by 32 days costs you 2 months of interest, not just 1.07 months. This is why I always advise clients to pay tax as close to the start of a month as possible: paying on 1 May versus 30 April makes no difference in interest, but paying on 2 May costs you an extra full month's worth of 234A or 234B because partial months round up. The rule is in Section 234A(1), 234B(1) and 234C(1) read with the proviso.
234C charges 1% per month on the shortfall against the cumulative percentage required by each due date: 15% by 15 June, 45% by 15 September, 75% by 15 December and 100% by 15 March. The interest period is 3 months for the first three instalments and 1 month for the last. Example: total liability Rs 4 lakh, paid Rs 50,000 by 15 September instead of required Rs 1.8 lakh. Shortfall Rs 1.3 lakh × 1% × 3 = Rs 3,900 for that instalment alone. The shortfall at each cutoff is computed independently. Capital gains and dividend income get a relaxation: pay in the next instalment after the gain arises.
Yes. 234B is computed on the assessed tax minus TDS already credited and advance tax already paid. So TDS reflected in your Form 26AS or AIS reduces the base on which 234B interest runs. If your total liability is Rs 1,20,000, TDS is Rs 90,000 and you've paid no advance tax, the assessed-tax shortfall as on 31 March is Rs 30,000. 234B runs at 1% per month on Rs 30,000 from April onwards. If TDS had been Rs 1,10,000 instead, the shortfall would be Rs 10,000 and the 90% threshold check would be triggered (110/120 = 91.6% > 90%), so 234B may not apply at all.
No. Section 234A interest is charged only on the unpaid tax liability outstanding as on the ITR due date. If your total tax is fully covered by TDS and advance tax (or you have a refund situation), there's no unpaid balance, and 234A does not apply even if you file the ITR years late. However, if you're in a refund position, late filing means delayed refund and possible loss of carry-forward losses, which is its own cost. The Supreme Court in CIT vs Pranoy Roy settled this: 234A is compensatory, not penal, so it requires an actual unpaid sum to bite.
234C is locked in by 31 March; nothing you do after that helps. The only way to avoid 234C is to pay each advance-tax instalment by 15 June, 15 September, 15 December and 15 March in the right cumulative percentages. 234B can still be minimised: pay self-assessment tax via Challan 280 as early in April or May as possible, before filing the ITR. Each month you defer adds another 1%. Pull up your AIS, estimate liability, deduct TDS already credited, and pay the balance immediately. I usually push clients to clear self-assessment tax in the first week of April once books are roughly closed.