Intimation under Section 143(1) — what it means and what to do

Short answer: an intimation under Section 143(1) is not a scrutiny notice. It is the result of your return being processed — checked for arithmetic and a narrow list of prima facie adjustments against data the Department already holds. Almost everyone gets one. It needs action only if it shows a demand, or a refund smaller than you claimed.

If it does, the route depends entirely on why the numbers differ — and the window for one route is 30 days while another runs four years.

What it actually is

When you file, the return goes to the Centralised Processing Centre, which processes it under Section 143(1). That processing is mechanical: it recomputes your total income and tax after checking the return for arithmetical errors and a limited set of adjustments, and matches your tax credits against its own records.

The intimation sets out the result in two columns — what you reported, and what the Department computed. Reading it is a matter of finding the row where the two disagree. Everything else follows from that one line.

The PDF is password-protected: PAN in lower case followed by date of birth as DDMMYYYY, no space.

Three outcomes are possible:

What CPC is permitted to adjust

This is the part most people do not realise: processing under Section 143(1)(a) is not an open re-examination of your return. Only a defined list of adjustments is permitted:

• an arithmetical error in the return;
• an incorrect claim apparent from information in the return — which means a claim inconsistent with another entry in the same return, an entry for which required supporting information was not furnished, or a deduction exceeding a statutory limit expressed as an amount, percentage or ratio;
• disallowance of a loss claimed where the return for the earlier year in which the loss arose was filed after the due date;
• disallowance of expenditure or income indicated in the audit report but not taken into account in the computation;
• disallowance of deductions under Section 10AA or under the Part C deductions in Chapter VI-A where the return was filed after the due date under Section 139(1).

There was also a clause permitting addition of income appearing in Form 26AS or Form 16A but not included in the return. That clause has not applied to returns for assessment years from 2018-19 onward, so an addition made on that basis alone is outside the permitted scope.

Note the distinction it creates. Restricting a TDS credit to what appears in Form 26AS is not an addition to income — it is the tax-credit side of the computation, and it remains part of processing. That is why a 26AS mismatch still produces a demand even though the income-addition clause no longer operates.

What CPC cannot do at this stage is form a view on a debatable question — whether an expense is allowable, whether a receipt is capital or revenue, whether your facts satisfy a condition. Those require scrutiny under Section 143(2), not summary processing. An adjustment that decides a genuinely arguable point is open to challenge on precisely that ground.

Why the numbers usually differ

In rough order of frequency:

1. Tax regime mismatch. The new regime under Section 115BAC is now the default. A return processed under it will not allow the old-regime deductions — 80C, 80D, HRA and the rest. Where the option to be taxed under the old regime was not validly exercised, including by filing Form 10-IEA where that is required, the deductions are disallowed and the demand can be substantial. This has become one of the most common causes of an unexpected 143(1) demand.
2. TDS credit not matching Form 26AS. The deductor has not filed its TDS statement, has filed it against the wrong PAN, or has reported it in a different period.
3. Income in AIS not in the return. Savings and fixed-deposit interest, dividends, and interest on income-tax refunds are the usual omissions.
4. A deduction exceeding its statutory cap — most often 80C beyond ₹1.5 lakh across all instruments, or 80D beyond the applicable limit.
5. Late filing consequences. A return filed after the due date under Section 139(1) loses the Part C Chapter VI-A deductions and the ability to carry forward losses, and both are picked up in processing.
6. Challan not matched. Self-assessment or advance tax paid but tagged to the wrong assessment year, wrong PAN or wrong major head, so it does not appear against your account.
7. Interest under Sections 234A, 234B and 234C computed on the recomputed figures, which can turn a small difference into a larger demand than expected.

If an adjustment is only proposed: the 30-day window

Where an adjustment is proposed under Section 143(1)(a), it cannot simply be made. The Department must first put it to you, and you have 30 days to respond through the e-filing portal under Pending Actions and e-Proceedings.

This window matters more than any other step in the process. A response filed within it is considered before the adjustment is made. If no response is filed, the adjustment is made as proposed — and what could have been resolved with an explanation becomes a demand you now have to unwind through rectification or appeal.

Responding does not mean agreeing. If the proposal is wrong, say so, with the workings and documents that show it.

If the intimation is already final: rectification or appeal?

Two routes, and choosing wrongly is expensive.

The trap is the asymmetry. Rectification runs four years; the appeal window runs thirty days. Filing a rectification for what is really a legal dispute, waiting for it to be rejected, and only then thinking about appeal will usually mean the appeal window has closed. Where the disagreement is substantive, the appeal position should be protected first.

Where the cause is a deductor's error, note the sequence: the deductor must correct and refile the TDS statement so the credit appears in Form 26AS, and only then does a rectification request have something to work with. Filing rectification before the deductor acts achieves nothing.

The thing people misread

An intimation under Section 143(1) is not an assessment.

A return processed without adjustment, and a refund received, are not findings that your return was correct. The Department can still select the return for scrutiny under Section 143(2), and can still reopen it under Section 148 where the conditions for reassessment are satisfied.

This matters directly for anyone who has received a refund on a claim they cannot substantiate. The refund is not the end of the matter — it is summary processing, and the position can be revisited. What that means in practice is covered in the guide to notices on deductions and exemptions claimed.

Timelines at a glance

Under the Income-tax Act 2025

Returns for AY 2026-27 and earlier are processed under the 1961 Act. For tax year 2026-27 onward the equivalents are:

The section mapping guide covers the wider renumbering, and which Act applies to your return sets out the transition.

This note explains the general position on processing under Section 143(1). What to do about a particular intimation depends on the specific adjustment made and the evidence behind your return, and should be confirmed against them before a rectification or appeal is filed.