Filed your return late, or paid less advance tax than you should have? Use this calculator to estimate the extra you owe as a late filing fee under Section 234F and interest under Sections 234A and 234B for AY 2026-27. Interest under 234C is explained below.
The four charges, in plain words
Four sections add to your bill when you file late or pay tax late. Here is what each one means.
Section 234F: late filing fee
For a person legally required to file, section 234F generally charges Rs 5,000 for late filing, limited to Rs 1,000 where total income does not exceed Rs 5 lakh. A voluntary return does not attract the fee merely because it is filed after the ordinary due date.
Section 234A: interest for filing late
If you file after the due date and still owe tax, you pay interest at 1 percent for every month or part of a month on the unpaid amount, from the day after the due date until you file.
For AY 2026-27, CBDT Circular 07/2026 (28 September 2026) moved the return due date for companies and audit cases from 31 October to 21 November 2026, and the calculator uses the new date. The circular does not mention section 234A, so the safe course was to pay any self-assessment tax by 31 October 2026. If you paid it later, check with your tax adviser whether section 234A interest applies.
Section 234B: interest for short advance tax
Section 234B tests advance tax against 90% of assessed tax after eligible TDS/TCS and other statutory credits. It applies where advance-tax liability exists, including the Rs 10,000 test and exceptions. Interest is normally 1% per calendar month or part from 1 April 2026 for this assessment year. Payments and later assessment changes affect the final working.
Section 234C: interest for late instalments
This is for paying your advance tax instalments late during the year, even if the year-end total is fine. Because it depends on each instalment, it is best worked out alongside the schedule in our advance tax estimator, and it is not part of the figure above.
How to avoid these
File by the statutory due date for your category and pay the required advance-tax instalments on time. The 90% section 234B test is not permission to leave the final 10% unpaid: section 234C and the 100% March instalment are separate. Use the AY 2026-27 form/deadline guide. The current-year advance-tax planner covers a different income year.
This is an estimate for general guidance and is not tax advice. Interest is charged on a month or part of a month basis, and exact figures depend on your assessment. Please confirm with a qualified professional.
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Frequently asked questions
What is the late fee for filing ITR after the due date?
For a person required to file, the usual fee is Rs 5,000, limited to Rs 1,000 if total income does not exceed Rs 5 lakh. No fee arises solely from late timing where the person was not required to file.
How much is interest under Section 234A?
1 percent for every month or part of a month on the unpaid tax, from the day after the due date until you file your return.
When does Section 234B apply?
Where advance tax was payable but paid at less than 90% of assessed tax after eligible credits. The tool separates TDS/TCS from advance tax and counts calendar months or parts from 1 April 2026. Exempt cases, interim payments and later assessment adjustments need their own working.
What is the difference between 234B and 234C?
234B is for paying too little advance tax for the year as a whole, while 234C is for paying the instalments late during the year. Both run at 1 percent a month.
Can I avoid 234A interest by paying tax but filing late?
234A interest is on unpaid tax, so paying your tax reduces it, but the 234F late fee still applies for filing after the due date.
Official reference: Income-tax Act, 1961 (as amended by the Finance Act, 2026), sections 234A, 234B, 234C and 234F, Income Tax Department. From Tax Year 2026-27 onward, see the Income-tax Act, 2025.
Related free calculators: TDS late fee and interest calculator.
Official source: Always confirm the latest interest and late-fee provisions at incometax.gov.in.
This calculator is for FY 2025-26 / AY 2026-27 under the earlier Act. It assumes no interim self-assessment payments and full balance payment on filing; it does not calculate 234C, 234-I or ITR-U additional tax.
Sources: Earlier Act, sections 234A/234B/234F; Finance Act 2026 filing changes.