Missed the ITR deadline? s.234F fee + s.234A interest, computed

Missing the ITR deadline creates two different calculations. Section 234F is a filing fee. Section 234A is interest on unpaid net tax. They are not the same charge, they do not use the same base, and one can apply when the other does not.

For FY 2025-26 (AY 2026-27), the due dates below come from Section 139(1) Explanation 2 as substituted by the Finance Act 2026 (effective 1 March 2026, deemed always substituted). Note the 31 August date — it is new, and founders with business income are the group it affects.

This guide gives the arithmetic under Sections 234A, 234B, 234C and 234F and a founder's checklist for separating the four questions.

First, identify the return category

A missed calendar date is not enough to conclude the return is belated: confirm the category above and check the CBDT position for the year before finalising.

Section 234F: the flat fee

"Where a person required to furnish a return of income under section 139, fails to do so within the time prescribed in sub-section (1) of the said section, he shall pay, by way of a fee, a sum of five thousand rupees: Provided that if the total income of the person does not exceed five lakh rupees, the fee payable under this section shall not exceed one thousand rupees" (s.234F(1), ITA 1961).

Three consequences follow:

• The fee applies only to a person required to file under Section 139. A person with no income who is under no filing obligation and files voluntarily does not attract it.
• There is no daily multiplication. The fee applies once when the belated return is filed: ₹5,000 where total income exceeds ₹5 lakh, capped at ₹1,000 where it does not — in every return category, including audit cases.
• Examples: income ₹8 lakh, filed late → ₹5,000. Income ₹3.5 lakh, filed late → ₹1,000.

So the practical first step is to classify total income correctly, then allow for the fee as a one-time item. Do not use days late to inflate s.234F.

Section 234A: interest on unpaid tax

Section 234A is a different calculation: "the assessee shall be liable to pay simple interest at the rate of one per cent for every month or part of a month comprised in the period commencing on the date immediately following the due date" (s.234A(1), ITA 1961). It applies where tax, net of advance tax, TDS/TCS and applicable reliefs and credits, remains outstanding when the return should have been filed.

The period ends "on the date of furnishing of the return" where a return is filed late — and only "where no return has been furnished" does it end on completion of the assessment under Section 144 (s.234A(1)(a)-(b)). It is not "whichever is earlier".

The Section 234A examples:

• Tax due ₹1,00,000, return filed two months late: ₹1,00,000 × 1% × 2 = ₹2,000.
• Tax due ₹5,00,000, return filed four months late: ₹5,00,000 × 1% × 4 = ₹20,000.
• Tax due ₹2,00,000, filed 45 days late: 45 days rounds to two months, so ₹2,00,000 × 1% × 2 = ₹4,000.

The "part of a month" rule is the trap. Do not prorate the delay into calendar days. Count whole-or-part months, with a partial month treated as a full month. Where net tax payable is nil because TDS and other credits fully cover the liability, s.234A interest is nil even if filing is late — confirm the computation with your CA.

A combined example

Suppose a founder with business income (non-audit) has total income of ₹8 lakh, net tax payable of ₹1,00,000 after TDS and advance tax, and files the FY 2025-26 return two months after the applicable due date — 31 August 2026, not 31 July.

That is not necessarily the total amount payable on the return. It excludes the underlying tax and any s.234B or s.234C interest that may apply, and it assumes the due date was not extended and that the net-tax base has been correctly computed.

Where sections 234B and 234C fit

A late return may expose an advance-tax problem as well.

Section 234B charges simple interest at 1% per month or part thereof where advance tax paid is less than 90% of assessed tax. The period runs "from the 1st day of April next following such financial year to the date of determination of total income under sub-section (1) of section 143 and where a regular assessment is made, to the date of such regular assessment" (s.234B(1)) — not to the date you actually pay. Example: assessed tax ₹5,00,000, advance tax ₹4,00,000 → ₹1,00,000 shortfall; five months → ₹5,000.

Section 234C charges interest for deferment of advance-tax instalments, computed on "the tax due on the returned income" (not assessed tax): 1% per month for three months on shortfalls from the 15%, 45% and 75% cumulative levels (15 June, 15 September, 15 December), and 1% on the shortfall from 100% at 15 March (s.234C(1)(a)). Two reliefs matter: no interest on the June/September shortfall where advance tax paid by those dates is at least 12%/36% of the tax due on returned income (proviso to s.234C(1)(a)), and taxpayers under s.44AD/44ADA have a single 15 March instalment (s.234C(1)(b)).

What founders should do after missing a date

• Identify the return category and applicable due date — 31 July, 31 August, 31 October or 30 November, per the table above.
• Check whether a CBDT extension changes the due date.
• Calculate total income for the s.234F band: above ₹5 lakh or ₹5 lakh and below — and confirm a filing obligation exists at all.
• Calculate net tax outstanding after TDS, advance tax and applicable reliefs and credits.
• Count s.234A months, treating a part month as a full month.
• Separately test the advance-tax conditions for s.234B and each s.234C instalment, using tax due on returned income.
• Preserve the computation, challans, TDS evidence and filing acknowledgement.
• Review the portal's final demand before treating the matter as closed.

The worst process is to file first and reconstruct the numbers later. The better process is to prepare a short computation that shows the due date, income band, net tax base, months, and each applicable section. Your CA can then review facts rather than reverse-engineer a portal total.

FAQ

Is s.234F charged per day?

No. A flat fee applied once: ₹5,000 where total income exceeds ₹5 lakh, capped at ₹1,000 where it does not — and only for a person required to file under Section 139.

Can s.234A be zero even when the return is late?

Yes, where net tax payable is nil because TDS and other credits fully cover the liability. Confirm the specific case.

Does 45 days late mean 1.5 months for s.234A?

No. 45 days counts as two months, because a part of a month counts as a full month.

Are s.234B and s.234C automatically part of every late return?

No. They are separate advance-tax tests. Run them only after reviewing assessed (or returned) tax, TDS, advance tax and instalment payments.

Does filing late change the underlying tax?

Sections 234A and 234F add fee and interest. They do not replace the underlying tax computation. Recompute the return itself and then add the applicable statutory amounts.

Statutory basis

• Section 234F — late ITR filing fee: ₹5,000, capped at ₹1,000 where total income ≤ ₹5 lakh (s.234F(1) proviso)
• Section 234A — 1% per month or part thereof from the day after the due date (s.234A(1))
• Section 234B — 1% per month where advance tax < 90% of assessed tax (s.234B(1))
• Section 234C — 1% on instalment shortfalls from tax due on returned income, with 12%/36% safe harbour and single 15 March instalment for s.44AD/44ADA (s.234C(1))
• Due dates — s.139(1) Explanation 2 as substituted by the Finance Act 2026 (31 July / 31 August / 31 October / 30 November)

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See also

• Every GST late fee in one place: GSTR-1, GSTR-3B, GSTR-9 (FY 2025-26)
• Section 43B(h): the 45-day MSME payment rule that changes your year-end

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See Also

• Every GST late fee in one place: GSTR-1, GSTR-3B, GSTR-9 (FY 2025-26)
• ROC Late Filing Fee Under Section 403: ₹100 Per Day for E-Forms AOC-4, MGT-7, DIR-3
• Section 234A Interest: 1% Per Month on Tax Unpaid When ITR Filed Late