Missed the ITR Deadline for AY 2026-27? Belated, Revised and Updated Returns Explained

TL;DR: If you missed your due date for AY 2026-27 (the year in which you report income earned in FY 2025-26), you have not run out of options — but each one costs something different. A belated return under Section 139(4) can be filed up to 31 December 2026, and carries a Section 234F fee of Rs 5,000, or Rs 1,000 if your total income does not exceed Rs 5 lakh. A revised return under Section 139(5) now runs all the way to 31 March 2027 — the Finance Act, 2026 extended that window, but it also created a new Section 234-I fee for revising in the last three months of it. And if even the belated door shuts, an updated return under Section 139(8A) remains, at a much steeper price. The expensive part of filing late is usually not the fee. It is the loss carry-forward and the regime choice you quietly forfeit.

1. First, which law even applies?

This trips people up badly this season, so it is worth thirty seconds. The Income-tax Act, 2025 came into force on 1 April 2026 and introduced the single "Tax Year" concept in place of the old previous-year/assessment-year pair. But it applies to income earned from 1 April 2026 onward — that is Tax Year 2026-27.

The return you are filing right now covers FY 2025-26, income earned up to 31 March 2026. That is still assessed under the Income-tax Act, 1961, as AY 2026-27. Every section number in this article — 139(1), 139(4), 139(5), 139(8A), 234A, 234F — is a 1961 Act section, and that is the correct frame for this filing.

2. The due dates that actually applied for AY 2026-27

The split between 31 July and 31 August is new, and it is permanent. The Finance Act, 2026 did not merely extend a date — it substituted Explanation 2 to Section 139(1) with the table above, with effect from 1 March 2026.

Read the second row carefully, because it is the one people misdescribe. The statutory test is whether you have income from business or profession and your accounts are not required to be audited. It is not "you file ITR-3 or ITR-4". The two usually land in the same place — a freelancer under 44ADA or a small trader under 44AD does file ITR-4 and does get 31 August — but the law keys off the nature of your income, not the form you happen to pick. Someone with only salary and capital gains had 31 July, whichever form they used.

So if you are a freelancer or small-business filer reading this in late August, check carefully: you may still be inside the original window rather than in belated territory at all. That distinction is worth real money, as section 4 explains.

3. Route 1 — the belated return, Section 139(4)

A belated return is simply the original return, filed after the due date. For AY 2026-27 it may be furnished on or before 31 December 2026, or before the assessment is completed, whichever happens first. That second limb matters: if the department completes assessment in November, your window closes in November.

What it costs

The 234F fee is a flat, automatic levy — the portal computes it and will not let the return through without it. Section 234A interest is different: it runs only on tax that is still unpaid after credit for TDS, TCS and advance tax. If your employer deducted enough TDS and nothing further is due, 234A can be nil even on a late return. Note that "part of a month" means a single day into a new month costs a full month's interest, so filing on the 1st and filing on the 28th cost the same.

What it quietly takes away

This is the part that costs more than the fee, and it is the reason to file on time even when no tax is payable.

• Loss carry-forward is forfeited. Under Section 139(3) read with Section 80, business losses and capital losses can only be carried forward to future years if the return was filed within the Section 139(1) due date. File belated and those losses are gone — you cannot set them off against next year's gains. A trader sitting on a Rs 4 lakh capital loss loses the right to shelter Rs 4 lakh of future gains.
• Two exceptions survive. House-property loss under Section 71B and unabsorbed depreciation under Section 32(2) can still be carried forward even from a belated return. These are the carve-outs, not the rule.
• The old regime may no longer be available. The new regime under Section 115BAC is the default. Opting out requires the election to be made by the Section 139(1) due date — and for taxpayers with business or professional income, that means Form 10-IEA filed on or before the due date. Miss it and you are taxed under the new regime for that year, which for someone with a large 80C, 80D and housing-interest stack can cost far more than the Rs 5,000 fee. If your tax position depends on the old regime, treat the due date as hard.

4. Route 2 — the revised return, Section 139(5)

A revised return is for a return you already filed that turns out to be wrong or incomplete — a missed interest income, a forgotten deduction, the wrong bank account, a mismatch against your AIS.

The window has just been extended. The Finance Act, 2026 substituted Section 139(5) outright. A revised return for AY 2026-27 may now be furnished at any time before the end of the relevant assessment year — that is, up to 31 March 2027 — or before the assessment is completed, whichever is earlier. The old rule cut this off at 31 December of the assessment year, so this is a genuine three-month gain, and it is the most useful change of the year for anyone still reconciling against Form 26AS and the AIS late in the season.

But there is now a fee: Section 234-I

The same Act inserted a brand-new Section 234-I, and the substituted Section 139(5) is expressly made "subject to" it. The extra three months are not free. Where a revised return is furnished in the final three-month slice of the window — the Act describes it as beyond nine months but before twelve months from the end of the relevant year — a fee applies:

In practical terms for AY 2026-27: revise on or before 31 December 2026 and there is no 234-I fee; revise between 1 January and 31 March 2027 and the fee applies. So the extension is real, but it is a paid extension. If you already know your return needs correcting, doing it before the new year saves Rs 5,000 for most filers.

One honest caveat: read absolutely literally, the nine-and-twelve-month wording in Section 234-I would point past the end of the Section 139(5) window itself, which cannot have been intended. The reading above — measuring from the end of the financial year, so the fee starts on 1 January — is how the department's own guidance and the professional commentary both treat it, and it is the only reading that lets the section operate at all. Watch for a CBDT clarification if you are cutting it fine.

Three things people get wrong about revised returns:

• You can revise a belated return. The substituted Section 139(5) says so on its face — it applies to a person who has furnished a return under sub-section (1) or sub-section (4). Filing late does not lock you out of correcting the figures afterwards.
• A revision replaces the original entirely. It is not a patch. The revised return stands in place of what you filed, and it must be verified in its own right, or it is not a return at all.
• Revising does not undo what a belated original cost you. If the first return was belated, the loss carry-forward and the regime election were already extinguished at that moment. Revising in February does not bring them back. This is the most expensive misconception in the whole area.

5. Route 3 — the updated return, Section 139(8A)

If 31 December 2026 passes with no return filed at all, the remaining route is ITR-U, the updated return under Section 139(8A). It exists to let taxpayers voluntarily report income they left out, and it is priced to make sure you would rather have filed on time — additional tax on top of the tax and interest, rising the longer you wait.

ITR-U comes with hard limits. As a rule it cannot be a return of loss, cannot reduce the tax liability shown in your earlier return, and cannot create or increase a refund. It is a one-way street for declaring more income, not for fixing something in your favour. We have covered the mechanics and the cost ladder separately — see our step-by-step ITR-U guide and the Section 140B penalty ladder.

There is one exception, and the Finance Act, 2026 just widened it. Where you had furnished a return of loss within the Section 139(1) due date, the sixth proviso lets you file an updated return that turns that loss into income — and, as amended, one that merely reduces the loss as well. The first proviso's bar on a "return of a loss" is now expressly subject to that carve-out. So a taxpayer who filed a loss return on time and later realises the loss was overstated is not shut out. Note the precondition: the original loss return had to be on time.

The Finance Act, 2026 also touched this route. An updated return may now be furnished in pursuance of a notice under Section 148, within the period that notice specifies — and where you take that path, you cannot then file a return under that notice in any other manner. The price is steep: new Section 140B(3A) increases the additional income-tax by a further 10% of the aggregate of tax and interest payable. Useful to know it exists; not somewhere you want to end up.

6. Which route applies to you

7. A worked example

Ravi is salaried, total income Rs 9.4 lakh, files ITR-1. His due date was 31 July 2026. He files on 14 October 2026. TDS deducted by his employer was Rs 4,000 short of his final liability.

• Section 234F fee: total income exceeds Rs 5 lakh, so Rs 5,000.
• Section 234A interest: Rs 4,000 unpaid, from 1 August to 14 October — August, September and part of October count as three months. 1% x 3 x Rs 4,000 = Rs 120.
• Total extra cost: Rs 5,120, plus the Rs 4,000 tax he owed anyway.

Now change one fact. Suppose Ravi also had a Rs 2 lakh short-term capital loss from equity trading. Because he filed belated, that loss cannot be carried forward. If he would have used it against gains next year at 20%, the real cost of filing late is not Rs 5,120 — it is closer to Rs 45,000.

8. Five mistakes worth avoiding

1. Filing but not verifying. An unverified return is treated as never filed. You have 30 days from filing to e-verify, and the belated deadline does not pause while you forget.
2. Assuming an extension is coming. The 31 July 2026 date for AY 2026-27 passed without one. A due date is only extended when the CBDT actually notifies it — and the 31 August date for non-audited business and professional income is now the statute's own date, not an extension of anything.
3. Skipping the return because tax was already deducted. If your income crosses the threshold, the obligation to file stands on its own, and a refund cannot be claimed without a return.
4. Filing belated on the assumption you can pick the old regime later. You generally cannot. Decide the regime before the due date, not after.
5. Confusing the two Acts. The Income-tax Act, 2025 and its "Tax Year" language do not govern this return. FY 2025-26 is a 1961 Act year.

Sources

• Income-tax Act, 1961 — Sections 139(1), 139(3), 139(4), 139(5), 139(8A), 80, 71B, 32(2), 115BAC, 234A and 234F.
• Income Tax Department, e-filing portal help — "Income Tax Returns": belated return for AY 2026-27 on or before 31 December 2026 or before completion of assessment, whichever is earlier; Section 234F fee of Rs 1,000 (total income up to Rs 5 lakh) or Rs 5,000 otherwise; revised return for AY 2026-27 up to 31 March 2027.
• Finance Act, 2026 — Gazette of India, Extraordinary, Part II Section 1, No. 9, dated 30 March 2026. Clause 5 substitutes Explanation 2 to Section 139(1) with the due-date table reproduced above, substitutes Section 139(5) (revised return before the end of the relevant assessment year, subject to Section 234-I, and expressly available to returns furnished under sub-section (4)), and amends Section 139(8A) to allow an updated return in pursuance of a Section 148 notice. Clause 6 inserts Section 140B(3A). Clause 16 inserts new Section 234-I. All with effect from 1 March 2026.
• Income-tax Act, 2025 — in force 1 April 2026, applicable from Tax Year 2026-27, i.e. to income earned on or after 1 April 2026.

This article states the position for AY 2026-27 as at 25 August 2026. Due dates can be extended by CBDT notification and the figures above can change; confirm the current position on the Income Tax Department e-filing portal before you act. Nothing here is advice on your individual facts — for a specific case, particularly one involving carried-forward losses or a regime election, consult a qualified tax professional.