A return is defective if it does not answer the conditions in the Explanation to s.139(9) — annexures and columns filled in, the computation of tax, the s.44AB audit report, proof of taxes paid, the accounts, and, where the accounts have been audited, the audited accounts with the auditor's report. The officer intimates the defect and gives fifteen days, extendable on application in his discretion. If it is not cured in time the return is treated as an invalid return and the Act applies as if you had never filed, which is what takes out the loss carry-forward and the due-date deductions.
The sub-section is one sentence and it is worth reading before arguing about anything else. "(9) 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". There is then a proviso: "Provided that 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."
What makes a return defective is not at large. The Explanation to the sub-section lists the conditions, and the departmental text of the section sets them out as: the annexures, statements and columns of the return relating to computation of income duly filled in; a statement of the computation of tax payable; the report of the audit under s.44AB where that section applies; proof of the tax deducted or collected at source, advance tax and self-assessment tax claimed to have been paid; copies of the accounts — the profit and loss account and balance sheet — where regular books of account are maintained; where the accounts have been audited, copies of the audited profit and loss account and balance sheet and the auditor's report, together with the cost audit report where a cost audit has been conducted; and, where regular books of account are not maintained, a statement showing the turnover or gross receipts, the expenses and the net profit. A defect notice that does not identify which of those conditions is said to be unmet is answerable on that ground alone.
The sharp end is the closing words. An unrectified defective return is not a late return; it is treated as no return at all. That is what removes the carry-forward of business and capital losses, because s.80 read with s.139(3) allows a loss to be carried forward only if the loss return was furnished within the s.139(1) time; it is what defeats the s.80AC condition that the deductions in Chapter VI-A heading C — s.80P among them — are allowed only where the return is furnished by the s.139(1) due date; and it is what puts the assessee at risk of a best judgment assessment on the footing that no return exists. The corpus already holds the cases on the s.80AC line, and on the s.119(2)(b) route for getting a late loss return condoned; nothing in s.139(9) itself supplies a remedy once the assessment has been made.
On the question practitioners actually ask — must the officer give the opportunity before he treats the return as invalid — the answer that can be sourced is textual rather than judicial. The invalidity in s.139(9) is not free-standing: it attaches only "if the defect is not rectified within the said period of fifteen days or, as the case may be, the further period so allowed", and that period only begins to run "from the date of such intimation". So an order treating a return as invalid without an intimation identifying the defect, and without the fifteen days having expired, has no statutory foundation. A High Court decision saying that in terms was not found on any page fetched for this note, and none is cited here.
What is sourced is the other half of the timing question. In Kunal Structure (India) Pvt Ltd v. Dy. CIT the Gujarat High Court held that where the defect is removed within the time the officer allowed, the return relates back to the date of the original filing, so the six-month limitation for a s.143(2) notice runs from the end of the financial year in which the original return was furnished. The Revenue's special leave petition was dismissed. That is the point to take when a scrutiny notice arrives late and the department dates the return to the day of rectification.
In the Income-tax Act 2025, the department's own section-mapping navigator puts section 139 of the 1961 Act at section 263. The wording of the defective-return provision in the new Act was not verified for this note.
s.139(9) is the commonest notice a small assessee meets after the s.143(1) intimation, and the only one whose default converts a filed return into no return. Practitioners treat it as a formality and reply late; the cost is not a fee under s.234F but the loss carry-forward, the Chapter VI-A deduction and, in a s.80P case, the whole exemption. The fifteen days are extendable, but only on an application made before they expire, and the proviso is discretionary, not a right.
I paid advance tax for the year but had not filed my return when the search took place. Can the department still call that income undisclosed?
Is a notice under s.143(2) a jurisdictional precondition, or merely a procedural step the Assessing Officer can skip?
I deducted TDS during the year but paid it after 31 March, though before I filed my return — can the expense still be disallowed under section 40(a)(ia)?
I filed a return showing a loss after the due date but before any assessment was made. Can the officer refuse to determine the loss and refuse to let me carry it forward?
No s.143(2) notice was issued at all. Does s.292BB save the assessment?
In the loss year the officer recorded that the loss could not be carried forward, and we did not appeal. The officer of the set-off year now says that finding is final against us. Is it?
I have given the excise authorities a bank guarantee for unpaid bottling fee. Does that count as actual payment under section 43B - and is bottling fee even covered by section 43B?
The AO cites Citizen Co-operative Society to deny my 80P claim. How far does it go?
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