You filed the return, the acknowledgement came, and then the mistake surfaced: a forgotten fixed-deposit interest entry, a bank account number one digit off, a deduction typed in the wrong field, a Form 26AS credit that never made it in. The Income-tax Act, 1961 gives more than one way to fix a filed return, but the ways are not interchangeable. Each has its own opening condition, clock and limits, and picking the wrong one wastes time you cannot recover. This note reads the four doors off the Department's published text of section 139 as amended by the Finance Act 2026.

A scope note first. Everything below is the Income-tax Act, 1961. The Department's e-filing help for assessment year 2026-27 still speaks of that Act. Returns for later years fall under the Income-tax Act, 2025, with its own section numbers, so do not carry this note over to them without checking.

## First, the door most people are looking for: the revised return

If you filed a return under section 139(1), or a belated return under section 139(4), and you then discover "any omission or any wrong statement therein", section 139(5) lets you file again:

> "If any person, having furnished a return under sub-section (1) or sub-section (4), discovers any omission or any wrong statement therein, he may, subject to the provisions of section 234-I, furnish a revised return at any time before the end of the relevant assessment year or before the completion of the assessment, whichever is earlier." (s.139(5), Income-tax Act 1961)

Three things in that sentence decide most cases.

The first is the trigger. The section is written for a person "having furnished a return" who "discovers any omission or any wrong statement". The door only opens if a return already exists. You cannot revise a return you never filed; that is the belated door below. "Wrong statement" is broad enough to cover a figure, a head of income, a bank detail or a claim you should not have made. The section does not grade mistakes into small and large.

The second is the window: "at any time before the end of the relevant assessment year or before the completion of the assessment, whichever is earlier" (s.139(5)). Read the first half carefully. It is the end of the assessment year, not of the previous year. The assessment year is the twelve months after the financial year in which the income was earned, so for assessment year 2026-27 it ends on 31 March 2027. The second half matters more than readers expect: if an assessment has already been completed for that year, the window has closed even though the calendar still looks open.

The third is the condition on the section's face: a revised return is "subject to the provisions of section 234-I" (s.139(5)).

### The fee under section 234-I

The Department's e-filing help for assessment year 2026-27 explains what that condition means in practice. Section 234-I is an additional fee payable on a revised return filed after 31 December of the assessment year, applicable from assessment year 2026-27 onwards, and for assessment year 2026-27 it applies from 1 January 2027. The fee stated there is ₹1,000 where total income is up to ₹5 lakh and ₹5,000 where total income exceeds ₹5 lakh (Income-tax e-filing portal help, ITR-2 online, FAQ on section 234-I). The return forms for the year carry a separate line for this fee. These figures come from the portal's help text, not from the statute, so confirm the current amount and the cut-off date on the portal before you file.

### This window is new

Section 139(5) was substituted by Act 4 of 2026 with effect from 1 March 2026, and the published text preserves the wording it replaced: "he may furnish a revised return at any time before three months prior to the end of the relevant assessment year or before the completion of the assessment, whichever is earlier" (s.139(5), Income-tax Act 1961, footnote on the pre-substitution text). The old rule shut the door three months before the assessment year ended, that is on 31 December. The current rule keeps it open to the end of that year, with the fee above applying to a revision filed after 31 December. If you are reading an article, a forum answer or a software prompt written before March 2026, the window you are being told about is not the one that applies now.

## If you never filed at all, that is a different door

A missing return is not a mistake in a return, so section 139(5) cannot help. Section 139(4) is the provision for the person who did not file within the time allowed:

> "Any person who has not furnished a return within the time allowed to him under sub-section (1), may furnish the return for any previous year at any time before three months prior to the end of the relevant assessment year or before the completion of the assessment, whichever is earlier." (s.139(4), Income-tax Act 1961)

Section 139(4) still speaks the older language, "three months prior to the end of the relevant assessment year", because the 2026 substitution reached section 139(5), not section 139(4). The two doors therefore do not close on the same day. A person who filed and wants to correct something has until the end of the assessment year, subject to the fee, while a person who never filed has until three months before that end, which is 31 December. If you are late and never filed, section 139(4) is the only route of the two, and its clock is the shorter one.

Once both of those have closed, the remaining door is the updated return.

## The updated return: forty-eight months, with conditions attached

Section 139(8A) is the long-stop. It applies to "any person, whether or not he has furnished a return under sub-section (1) or sub-section (4) or sub-section (5)", and it allows an updated return "at any time within forty-eight months from the end of the relevant assessment year" (s.139(8A), Income-tax Act 1961). The forty-eight months is itself recent: the published footnote records that "twenty-four" was substituted by "forty-eight" by Act 7 of 2025 with effect from 1 April 2025.

A long window is not an open one. Section 139(8A) prints a set of bars that decide eligibility before any question of computation arises.

**What an updated return may not be** (first proviso). It cannot be "a return of a loss"; it cannot have "the effect of decreasing the total tax liability determined on the basis of return furnished under sub-section (1) or sub-section (4) or sub-section (5)"; and it cannot "result in refund or increase the refund due" on the basis of the return already furnished (s.139(8A), first proviso, clauses (a) to (c)). In plain terms, an updated return is for disclosing more, not for asking for money back. If your mistake is that you overpaid, section 139(8A) is the wrong instrument.

The one loss-related exception is narrow. A person who sustained a loss and filed a return of loss within time "shall be allowed to furnish an updated return where such updated return is a return of income or such updated return has the effect of reducing the loss" (s.139(8A), sixth proviso).

**Who cannot file one at all** (second and third provisos). Under the second proviso, a person is not eligible where a search has been initiated under section 132, or books, documents or assets have been requisitioned under section 132A, in that person's case; where a survey has been conducted under section 133A, other than under sub-section (2A) of that section; or where a notice says seized or requisitioned material of another person belongs to, or relates to, that person. This applies for the year of the search, survey or requisition and any assessment year before it. Under the third proviso, no updated return can be furnished for the year where an updated return has already been furnished for it; where "any proceeding for assessment or reassessment or recomputation or revision of income under this Act is pending or has been completed" for that year; where specified information under four named Acts or under a tax treaty has been communicated to the person; where prosecution proceedings under Chapter XXII have been initiated; or where the person belongs to a class notified by the Board (s.139(8A), second and third provisos).

**The reassessment line.** "No updated return shall be furnished by any person where any notice to show-cause under section 148A has been issued in his case after thirty-six months from the end of the relevant assessment year", except where an order under section 148A(3) holds that it is not a fit case to issue a notice under section 148 (s.139(8A), fourth and fifth provisos). An updated return is not a way to get in front of a reassessment already put in motion on that footing.

## "Defective return" is a fourth, separate problem

Sometimes the Department does not dispute your figures at all. It says the return itself does not qualify as a return. Section 139(9) covers that:

> "Where the Assessing Officer considers that the return of income furnished by the assessee is defective, he may intimate the defect to the assessee and give him an opportunity to rectify the defect within a period of fifteen days from the date of such intimation or within such further period which, on an application made in this behalf, the Assessing Officer may, in his discretion, allow; and if the defect is not rectified within the said period of fifteen days or, as the case may be, the further period so allowed, then, notwithstanding anything contained in any other provision of this Act, the return shall be treated as an invalid return and the provisions of this Act shall apply as if the assessee had failed to furnish the return." (s.139(9), Income-tax Act 1961)

The consequence is stated in the same breath and it is the harshest in this section: the return "shall be treated as an invalid return", and the Act then proceeds "as if the assessee had failed to furnish the return". A defect ignored is not a minor blemish; it is treated as no return at all.

There is relief, but it is discretionary: "where the assessee rectifies the defect after the expiry of the said period of fifteen days or the further period allowed, but before the assessment is made, the Assessing Officer may condone the delay and treat the return as a valid return" (s.139(9), proviso).

## Step by step, once you spot the mistake

1. **Establish which return exists.** Find the acknowledgement for the year in question. If there is none, you are under section 139(4), not section 139(5), and the clock is "three months prior to the end of the relevant assessment year" (s.139(4)).
2. **Check whether an assessment is already complete.** Both section 139(4) and section 139(5) end the window at "before the completion of the assessment, whichever is earlier". A completed assessment is a hard stop regardless of the date.
3. **Decide whether the correction increases or decreases your liability.** If it increases income or liability and the revised window has closed, section 139(8A)'s forty-eight months may still be open, provided none of its bars applies. If it decreases liability or claims a refund, section 139(8A) is closed to you by its first proviso, so the revision window is the only route.
4. **Check the section 148A position before assuming section 139(8A) is available** (s.139(8A), fourth and fifth provisos).
5. **Reply to a defect intimation immediately.** You have fifteen days, extendable on application, with condonation only before the assessment is made (s.139(9) and proviso).
6. **Keep both acknowledgements.** The revision does not erase the first return from the record; the sequence shows the correction was made inside the window.

## The provisions, in one place

| Situation | Provision | Window |
| --- | --- | --- |
| Return filed, omission or wrong statement found | s.139(5) | End of the relevant assessment year or completion of assessment, whichever is earlier, subject to s.234-I |
| Never filed in time | s.139(4) | Three months prior to the end of the assessment year, or completion of assessment |
| Revision window over, liability increases | s.139(8A) | Forty-eight months from the end of the assessment year, subject to the provisos |
| Return held defective | s.139(9) | Fifteen days from intimation; condonation possible before assessment |

## What to do now

- **Next step:** locate the acknowledgement for the year and decide whether you are correcting a filed return (s.139(5)) or filing one you missed (s.139(4)).
- **Deadline:** a revision runs to the end of the assessment year or completion of assessment, whichever is earlier (s.139(5)). A first-time return under s.139(4) must be in three months before the assessment year ends (s.139(4)). A defect reply is due within fifteen days of the intimation (s.139(9)).
- **Consequence of delay:** an unremedied defect makes the return invalid, as if you had not filed (s.139(9)). A revised return filed after 31 December of the assessment year, for assessment year 2026-27 onwards, attracts the section 234-I fee (Income-tax e-filing portal help).

Have a CA review your facts before you act or file.

## FAQ

**The revised window has passed and I under-paid tax. Can I still correct it?**
Section 139(8A) allows an updated return within forty-eight months from the end of the relevant assessment year, if none of its bars applies and the correction does not reduce liability or produce a refund (s.139(8A)).

**I never filed for that year at all. Can I file now?**
Within the section 139(4) window, "before three months prior to the end of the relevant assessment year or before the completion of the assessment, whichever is earlier". After that, only under section 139(8A), on its conditions.

**I received a notice saying my return is defective. How long do I have?**
Fifteen days from the date of the intimation, or such further period as the Assessing Officer allows on an application. After that the return is treated as invalid, though rectification before the assessment is made may still be condoned (s.139(9) and proviso).

*This note states the provisions as published and is not a substitute for advice on your own assessment year, figures and notices.*

Canonical: https://www.harunraaj.com/blog/filed-itr-found-mistake-what-now