Think of Section 148 as the formal summons the tax department must send before it can reopen your old case. Under Section 147, the Assessing Officer (AO) has power to reassess income that 'escaped assessment' — but before doing that, the AO must knock on your door through a Section 148 notice. Without this notice, any reassessment is legally invalid. Courts have consistently struck down reassessments where this procedural step was skipped.
What does the notice demand? It requires you to file a fresh return of income for the relevant previous year — just like you would file under Section 139 (your normal ITR). The AO specifies a deadline in the notice itself. Once you file this return, the law treats it exactly like a regular Section 139 return. This means all normal assessment provisions — scrutiny under Section 143, best judgement assessment under Section 144 — apply to it as well.
The most exam-critical rule: AO must record reasons before issuing the notice. Sub-section (2) is a legal safeguard for taxpayers. Before touching the keyboard to draft the notice, the AO must write down his reasons for believing income has escaped assessment. This isn't a formality — the assessee has a legal right to demand these recorded reasons, and courts have repeatedly quashed reassessments where reasons were missing, vague, or an afterthought. For your exam: no recorded reasons = invalid notice = reassessment falls flat. This point is asked frequently as a 4-mark question in the context of "discuss the safeguards available to an assessee against reopening of assessments."
Don't confuse the 'reason to believe' standard (which lives in Section 147) with Section 148's job. Section 147 decides whether income escaped; Section 148 is the procedural step — issuing the notice and getting the return. Also, the provisos in the section deal with a transitional period from 1991–2005 regarding old scrutiny notice timelines. Skip these entirely for May 2026 — they have zero current exam relevance and exist only as legacy validating provisions.
Example 1: AO wants to reopen Rajesh's assessment
Rajesh filed his return for AY 2022-23, declaring total income of ₹6,00,000. The AO later receives information from a bank that Rajesh deposited ₹12,00,000 in cash during FY 2021-22, which he didn't explain in his return. The AO believes income of ₹12,00,000 escaped assessment.
Step 1: Before issuing any notice, the AO must record his reasons in writing — specifically, that cash deposits of ₹12,00,000 constitute escaped income based on bank data received.
Step 2: Only after recording these reasons, the AO serves a notice under Section 148 on Rajesh, asking him to file a return for AY 2022-23 within, say, 30 days.
Step 3: Rajesh files a return in response, declaring income of ₹18,00,000 (his original ₹6,00,000 + the ₹12,00,000 he now discloses).
Result: This return is treated exactly like a Section 139 return. The AO may now proceed with reassessment under Section 147. Rajesh also has the right to request a copy of the AO's recorded reasons.
---
Example 2: Can a notice without recorded reasons survive?
Ms. Iyer receives a Section 148 notice on 10 January 2026. She files her return as required. Later, she requests a copy of the AO's recorded reasons — but the AO admits no reasons were recorded before the notice was issued.
Step 1: Recorded reasons are mandatory under Section 148(2). The AO skipped this step.
Step 2: Ms. Iyer files a writ petition challenging the notice.
Result: The notice is invalid and liable to be quashed. The reassessment proceedings that follow also collapse. No recorded reasons = no valid Section 148 notice = no reassessment.
📖 Bare Act text — Section 148, Income Tax Act 1961
(click to expand)
(1) Before making the assessment, reassessment or recomputation under section 147, the Assessing Officer shall serve on the assessee a notice requiring him to furnish within such period as may be specified in the notice, a return of his income or the income of any other person in respect of which he is assessable under this Act during the previous year corresponding to the relevant assessment year, in the prescribed form and verified in the prescribed manner and setting forth such other particulars as may be prescribed; and the provisions of this Act shall, so far as may be, apply accordingly as if such return were a return required to be furnished undersection 139: Provided that in a case— (a) where a return has been furnished during the period commencing on the 1st day of October, 1991 and ending on the 30th day of September, 2005 in response to a notice served under this section, and (b) subsequently a notice has been served under sub-section (2) of section 143 after the expiry of twelve months specified in the proviso to sub-section (2) of section 143, as it stood immediately before the amendment of said sub-section by the Finance Act, 2002 (20 of 2002) but before the expiry of the time limit for making the assessment, re-assessment or recomputation as specified in sub-section (2) of section 153, every such notice referred to in this clause shall be deemed to be a valid notice: Provided further that in a case— (a) where a return has been furnished during the period commencing on the 1st day of October, 1991 and ending on the 30th day of September, 2005, in response to a notice served under this section, and (b) subsequently a notice has been served under clause (ii) of sub-section (2) of section 143 after the expiry of twelve months specified in the proviso to clause (ii) of sub-section (2) of section 143, but before the expiry of the time limit for making the assessment, reassessment or recomputation as specified in sub-section (2) of section 153, every such notice referred to in this clause shall be deemed to be a valid notice. Explanation.—For the removal of doubts, it is hereby declared that nothing contained in the first proviso or the second proviso shall apply to any return which has been furnished on or after the 1st day of October, 2005 in response to a notice served under this section.
(2) The Assessing Officer shall, before issuing any notice under this section, record his reasons for doing so.