ITR filing deadlines and common errors to avoid

Filing an income tax return is, for most individuals and small businesses, a once-a-year event. That makes it easy to forget the small operational details that turned out to matter last time and to repeat the same errors that triggered a notice the year before.

This note covers two things: the due dates that apply to different categories of taxpayer, and the six errors that, in our experience, account for the bulk of rectification requests and Section 143(1) intimations.

Due dates by category

The Income-tax Act sets different due dates depending on whether a taxpayer is subject to audit and whether they have international or specified domestic transactions. For assessment year 2026-27 (financial year 2025-26), the headline dates are:

• 31 July 2026 — Individuals, HUFs, and any other assessee whose accounts are not required to be audited. ITR-1, ITR-2, ITR-3 (without audit), and ITR-4 fall here.
• 31 October 2026 — Assessees who are required to get accounts audited under the Income-tax Act or any other law, and the partners of firms whose accounts are audited. ITR-3, ITR-5, and ITR-6 fall here.
• 30 November 2026 — Assessees required to furnish a report in Form 3CEB because of international transactions or specified domestic transactions under Section 92E.
• 31 December 2026 — Belated and revised returns for AY 2026-27 (unless an assessment has been completed earlier).

The tax audit report under Section 44AB must be furnished one month before the due date of filing the return — so 30 September 2026 for the 31 October cohort, and 31 October 2026 for the 30 November cohort.

Section 234F — what a late return costs

The fee under Section 234F applies whenever a return is filed after the original due date but on or before 31 December of the assessment year:

• Rs. 5,000 in the general case.
• Rs. 1,000 where the total income does not exceed Rs. 5 lakh.

This is a fee, not a penalty — it is automatic and not subject to discretionary waiver. Interest under Section 234A continues to run on any tax outstanding from the original due date until payment, regardless of whether the return is filed late or on time.

The six errors that account for most notices

Most of the Section 143(1) intimations and rectification requests we see fall into one of six categories. Each of these is preventable with a pre-filing checklist:

1. PAN, name, and date-of-birth mismatch

The name on the PAN database is what the Income Tax Department uses to match returns. If your return shows even a minor variation — a middle initial added or dropped, a surname spelt differently — the e-filing portal may reject the return, or worse, accept it but flag a verification problem later. The same applies to the date of birth.

Before filing, log in to the e-filing portal and verify that the PAN details, name, date of birth, and address shown match what you intend to file. Any correction needs to be done through NSDL/UTIITSL, not in the return itself.

2. Not reconciling Form 26AS, AIS, and TIS

Three statements are now in play: Form 26AS (TDS/TCS and tax payments), the Annual Information Statement (AIS, which captures a broader set of transactions including dividend, interest, and high-value spends), and the Taxpayer Information Summary (TIS, the processed view that flows into pre-filled returns).

The errors here usually take one of three forms:

• Income reported in AIS that the taxpayer was unaware of — fixed deposit interest from a bank they did not realise was paying, dividend on a small holding, or a property sale by a co-owner where they were treated as the seller for AIS purposes.
• TDS credit not appearing in 26AS because the deductor either did not file the TDS return or quoted the PAN incorrectly. The taxpayer cannot claim credit until the deductor corrects it.
• Mismatch in the pre-filled return because the AIS classification differs from the taxpayer's view. The AIS feedback mechanism exists to flag these.

3. Capital gains classification

The line between short-term and long-term capital gains depends on the asset class — twelve months for listed equity and equity mutual funds, twenty-four months for unlisted shares and immovable property, thirty-six months for debt mutual funds (held before 1 April 2023). Misclassification changes both the rate and the availability of indexation.

The other recurring error in this area is the treatment of capital gains from mutual fund SIPs, where each instalment has its own acquisition date for FIFO purposes. A redemption of one year's worth of units is rarely a single capital gain — it is twelve separate ones, each to be classified on its own merits.

4. Foreign asset and foreign income disclosure

Schedule FA (Foreign Assets) is mandatory for a resident and ordinarily resident individual who at any time during the year holds a foreign asset, foreign bank account, or beneficial interest in a foreign entity — regardless of the value involved. There is no de minimis threshold.

Common omissions include ESOPs in a foreign parent company, brokerage accounts opened while working abroad and left open after returning, and beneficial interests in family trusts. The penalties under the Black Money Act for non-disclosure are severe — far beyond the tax saved by leaving the asset off the return.

5. Choosing the wrong return form

ITR-1 is restricted to resident individuals with total income up to Rs. 50 lakh, with income only from salary, one house property, family pension, and other sources (excluding lottery and racehorses), and agricultural income up to Rs. 5,000. The moment any of those conditions is breached — a second house property, capital gains, foreign income, or directorship in a company — ITR-2 or ITR-3 becomes the right form.

Filing the wrong form risks the return being treated as defective under Section 139(9), with a fifteen-day window to rectify before the return is treated as never having been filed.

6. Bank account, IFSC, and verification details

Refunds are credited only to a pre-validated bank account in the taxpayer's own name. A wrong IFSC, an inactive account, or an account that has not been validated through the e-filing portal will hold up the refund even after the assessment is complete.

And finally, the return is not filed until it is verified — either through Aadhaar OTP, net banking, or by sending the signed ITR-V to CPC Bengaluru within thirty days. An unverified return is treated as not filed at all, with the late-filing consequences that follow.

A short pre-filing checklist

1. Confirm PAN details match the e-filing portal.
2. Download and reconcile Form 26AS, AIS, and TIS.
3. Confirm the correct ITR form for your facts.
4. Classify every capital transaction by date and asset class.
5. Disclose every foreign asset, regardless of value, in Schedule FA.
6. Pre-validate the bank account intended for refund.
7. File. Verify within thirty days. Save the acknowledgement.

None of this is glamorous, but the difference between a clean filing season and a year of notices comes down to whether these seven steps are done before submitting the return or after.

This article is for educational purposes and is not professional advice. Consult a qualified professional for advice on your specific situation.