ITR Late Filing Fee & Interest Calculator

Missing the income tax return due date does not cost you a percentage of your income. It costs two separate things, and this calculator keeps them apart so you can see exactly where the money goes: a fixed late filing fee under section 234F, and interest under section 234A on any tax that was still unpaid on the due date.

Late filing fee (section 234F)

₹5,000 if you file after the due date. If your total income is not more than ₹5,00,000 the fee is ₹1,000 instead. It is a flat amount: filing one day late and filing four months late cost the same fee.

Interest (section 234A)

Simple interest of 1% for every month or part of a month, from the day after the due date until the day you file, on the tax that was still unpaid. If there was no tax left to pay after TDS and advance tax, there is no interest, only the fee.

This calculator follows the Income-tax Act, 1961 as it applies to returns for assessment year 2026-27 (financial year 2025-26) and earlier. The new Income-tax Act, 2025 takes over from tax year 2026-27, with these charges carried under new section numbers. Check the rates against the portal if you are filing for a later year.

Late fee = ₹1,000 (income up to ₹5 lakh) or ₹5,000 (above) | Interest = unpaid tax × 1% × months late

• Interest is worked on the unpaid tax rounded down to the nearest ₹100, so ₹12,345 is treated as ₹12,300.
• A part of a month counts as a whole month. One day into a new month adds a full 1%.
• Interest runs from the day after the due date to the date you file the return, not to the date you pay, so file and pay together.
• The fee and the interest are added to the tax you owe and paid with the belated return as self-assessment tax.

For assessment year 2026-27, the usual due dates are 31 July 2026 for individuals, HUFs and others who do not need an audit, and 31 October 2026 for businesses and professionals whose accounts must be audited. Cases that need a transfer pricing report have a later date of 30 November. The government can extend these by notification, so check the date announced for the year you are filing.

If you miss the due date you can still file a belated return under section 139(4), up to 31 December of the assessment year. For assessment year 2026-27 that is 31 December 2026. The late fee and interest in this calculator apply to a belated return. After that date a normal belated return is no longer available, and the route is an updated return (ITR-U) which carries additional tax on top of the tax and interest.

• Loss carry-forward: most business and capital losses can be carried forward only if the return is filed by the due date. A belated return can lose that benefit, which is often worth more than the fee.
• Refund delay: a refund is processed only after the return is filed, so filing late delays your money.
• Advance tax interest is separate: if you did not pay enough advance tax during the year, interest under sections 234B and 234C applies on top. Use our advance tax interest calculator for that.
• No fee if you were not required to file: the fee applies to people who had to file a return. If your income was below the basic exemption limit and no other rule required you to file, you generally owe no fee. Confirm this with your adviser.

• File as early as you can. Interest grows by 1% of the unpaid tax each month, so the earlier you file, the less you pay.
• Pay the tax when you file, not later. Self-assessment tax paid before you file stops interest running on that amount from the date of payment.
• Keep your TDS certificates and Form 26AS or AIS ready. A mismatch is the most common reason a founder files late.
• If you are close to the 31 December cut-off, file a simple correct return first. A belated return is better than an updated return.

• Assuming the fee grows with the delay. The section 234F fee is fixed at ₹1,000 or ₹5,000, and it is the interest that grows.
• Counting days instead of months. Interest is charged per month or part of a month, so day-level counting understates the cost.
• Charging interest on the full tax. Interest applies only to the tax still unpaid after TDS, TCS and advance tax.
• Forgetting the fee is due even when there is no tax to pay. A refund case filed late still pays the section 234F fee.

From tax year 2026-27 (income earned from 1 April 2026) the Income-tax Act 2025 replaces the 1961 Act. This page uses the 1961 section numbers, which still apply to FY 2025-26 and earlier years. For the current year, the same rules sit under these new numbers:

• Section 234A → section 423 of the Income-tax Act 2025
• Section 234B → section 424 of the Income-tax Act 2025
• Section 234C → section 425 of the Income-tax Act 2025
• Section 234F → section 428 of the Income-tax Act 2025