An email from the Income Tax Department with “143(1)” in the subject line makes most people assume the worst. It usually is not. An intimation under Section 143(1) is simply the automated outcome of your return being processed — and the large majority of them either confirm your return or tell you a refund is on its way.
What matters is reading it correctly and, if there is a demand, responding inside the 30-day window.
What a 143(1) intimation actually is
When you file, your return goes to the Centralised Processing Centre. The system does not investigate you; it performs a defined set of automated checks — arithmetic accuracy, internal consistency, whether claimed deductions are permissible, and whether the tax credits you claimed match what is recorded against your PAN. It then produces a two-column comparison: as provided by you versus as computed under Section 143(1).
The three possible outcomes
| Outcome | What it means | Action needed |
|---|---|---|
| No demand, no refund | Your return was accepted as filed | None — keep it for your records |
| Refund determined | You paid more tax than due | None; track it via refund status |
| Demand payable | CPC computed a higher liability than you did | Respond within 30 days — agree, disagree, or revise |
How to open and read it
The intimation arrives by email and is also available under e-File → Income Tax Returns → View Filed Returns on the portal. The PDF is password protected: your PAN in lower case plus date of birth in DDMMYYYY, so PAN ABCDE1234F with DOB 1 January 1990 gives abcde1234f01011990.
Inside, ignore the boilerplate and go straight to the comparison table. Read down the two columns and find the first row where the figures differ — that single row is almost always the entire explanation for the demand.
What causes a demand, in order of frequency
- TDS claimed does not appear in Form 26AS. You claimed credit your employer or bank never correctly reported. CPC can only allow what is on record — see AIS vs 26AS.
- Income missing from the return. Typically savings or FD interest, dividends, or salary from a previous employer after a job change.
- A deduction disallowed. Commonly an Old Regime deduction claimed while filing under the New Regime, or an 80C claim exceeding ₹1.5 lakh.
- Regime mismatch. Your employer deducted TDS on one basis and you filed on the other, so the computation shifts.
- Advance tax or self-assessment tax not matched. Tax was paid but the challan details were entered incorrectly.
How to respond, step by step
- Log in to incometax.gov.in.
- Open Pending Actions → Response to Outstanding Demand.
- Locate the demand for the relevant assessment year and choose your response:
- Agree — pay the demand online and the matter closes.
- Disagree — select a reason such as demand already paid, TDS credit not given, or rectification required, and attach supporting details.
- Partially agree — pay the portion you accept and dispute the rest with reasons.
- Submit and keep the acknowledgement.
If the underlying problem is a genuine error in your own return, a revised return is usually the cleaner route than arguing the demand. For AY 2026-27 a revised return can be filed up to 31 December 2026. If the error is in the processing rather than your return, a rectification request under Section 154 is the right instrument.
How to avoid one next year
Almost every 143(1) demand traces back to a mismatch that was visible before filing. Reconcile your Form 16, Form 26AS and AIS against each other first; include every source of income, including interest and dividends; claim deductions only for the regime you are actually filing under; and re-check the final figure with our income tax calculator before you submit.
Frequently asked questions
What is an intimation under Section 143(1)?
It is the automated result of processing your return at the Centralised Processing Centre. The system recomputes your return after arithmetic checks and cross-verification against the tax credits on record, then issues a side-by-side comparison of what you reported and what it computed. It is not a scrutiny assessment and, in most cases, is not an accusation of anything.
Is a 143(1) intimation a bad thing?
Usually not. Most taxpayers receive one for every return they file. There are three possible outcomes: no change, meaning your return was accepted as filed; a refund determined; or a demand payable. Only the third requires action, and even then it is often caused by a mismatch that can be corrected.
How long do I have to respond to a 143(1) demand?
Thirty days from the date of the intimation. If you do not respond, the demand is generally treated as confirmed and can be recovered, including by adjusting future refunds under Section 245. Responding on time, even to disagree, keeps your options open.
What is the password to open the 143(1) PDF?
Your PAN in lower case followed by your date of birth in DDMMYYYY format, with no spaces. For PAN ABCDE1234F with date of birth 1 January 1990, the password is abcde1234f01011990.
What if I disagree with the demand?
Log in to the e-filing portal, go to 'Pending Actions' then 'Response to Outstanding Demand', and select 'Disagree with demand' or 'Partially agree', giving the reason and supporting details. If the underlying issue is a genuine mistake in your own return, filing a revised return is often the cleaner fix.
By when must the department issue a 143(1) intimation?
An intimation under Section 143(1) cannot be issued after nine months from the end of the financial year in which the return was filed. If no intimation is issued within that window, the return is generally taken as accepted as filed.
Official sources
Every figure and rule in this guide is checked against the official government sources below. Always confirm for your own situation before filing.