Missed the ITR Deadline? Belated ITR Filing for AY 2026-27 \u2014 31 December 2026 Last Date, Late Fee & Interest

If the July or August deadline slipped past you, do not panic — and do not wait until December either. This guide explains the exact last date, the fees, the interest math, what you lose by filing late, and the step-by-step filing process on the income tax portal.

What is a belated return?

A belated return is an income tax return filed after the normal due date but before 31 December of the assessment year. For AY 2026-27 (FY 2025-26), that means any return filed after your original deadline, up to 31 December 2026, counts as belated. It is fully legal and accepted by the tax department — but it comes with extra costs and fewer rights than an on-time return.

In the Income-tax Act 2025, belated returns are covered under Section 263 (the provision that replaced old Section 139). The belated-return window has not changed: it still closes on 31 December of the assessment year.

The deadlines that matter for AY 2026-27

Your original due date depends on the kind of taxpayer you are. The government has not announced any extension for AY 2026-27, so these dates stand:

If you missed any of these dates, the single last chance for a belated return is 31 December 2026.

Late fee: Section 428 (old Section 234F)

The late fee is flat — it does not depend on how much tax you owe, only on your total income:

The fee is auto-calculated by the e-filing portal when you file. It is a fee, not interest — it applies even if you owe zero tax. One small relief: if your gross total income is below the basic exemption limit and none of the mandatory-filing conditions apply, no fee is charged.

Interest: Section 423 (old Section 234A)

If any tax remains unpaid after the original due date, interest is charged at 1% per month (or part of a month) on the unpaid amount. The clock starts the day after your original due date and runs until you actually pay.

Example: your due date was 31 July 2026 and you pay on 20 October 2026. That is August (1 month) + September (1 month) + October — even 20 days counts as a full month (1 month). So 3 months of interest.

The formula:

Interest = unpaid tax × 1% × number of months (part months count as full)

Interest is separate from the late fee — you can end up paying both.

What you lose by filing late

The money is only half the story. A belated return costs you several rights:

• Loss carry-forward: Business losses, capital losses and speculative losses from FY 2025-26 cannot be carried forward to future years. Only unabsorbed depreciation is still allowed. Miss the deadline, and those losses die in the same year.
• Tax regime choice: If you have business or professional income, you needed to file Form 10-IEA by the original due date to opt out of the new tax regime. Filing belated locks you into the new regime for AY 2026-27. (Our Form 10-IEA step-by-step guide explains the rule, and our new-regime slabs table for FY 2026-27 shows what the new regime looks like.)
• Slower refunds: Belated returns are processed in a later batch. Your refund will come, but it will take longer than for on-time filers.
• Shorter correction window: Revised returns are allowed only till the same 31 December 2026 cut-off. File late, and you give yourself barely any room to fix mistakes. (Budget 2026 has proposed extending the revision window to 31 March with late fees for revisions after 31 December — until that becomes law, treat 31 December as final.)
• Advance-tax spillover: If you had unpaid advance tax, interest under the advance-tax provisions may already have been running — our advance-tax December instalment guide covers how those charges work.

Belated vs revised vs updated return — three different things

These terms get mixed up. Here is the simple version:

• Belated return — filed after the due date but by 31 December 2026. Costs you the late fee + interest.
• Revised return — filed to fix mistakes in an already-filed return, allowed till 31 December 2026. A belated return can itself be revised within this window.
• Updated return — a separate option that stays open up to 48 months from the end of the assessment year (so well past 31 December), but it costs additional tax (25% to 60% of the extra tax, depending on how late you are) and is meant for declaring missed income, not for claiming refunds or losses.

If 31 December 2026 passes and you never filed at all, the updated return is your only door back in — an expensive one.

Step-by-step: how to file a belated return on incometax.gov.in

1. Log in — go to incometax.gov.in, choose Login, and sign in with your PAN and password.
2. Start e-filing — from the dashboard, click e-File → Income Tax Return.
3. Pick the assessment year — select AY 2026-27 from the drop-down.
4. Select the return type — choose Belated Return (the portal shows Original / Revised / Belated).
5. Choose your ITR form — ITR-1 for salary + one house property, ITR-2 for capital gains, ITR-3/ITR-4 for business or presumptive income.
6. Fill in the details — salary, house property, other income, deductions you are eligible for, taxes paid (TDS/TCS/advance tax/self-assessment tax).
7. Let the portal compute — tax, interest under Section 423 and the late fee under Section 428 are calculated automatically. Review each line.
8. Pay what is due — use net banking, card or UPI. The challan will show tax, interest and fee as separate line items.
9. Validate and submit — click Validate, then Submit. The portal generates your ITR-V acknowledgement.
10. E-verify within 120 days — use Aadhaar OTP, net banking, or send the signed ITR-V to CPC, Bengaluru. Until e-verified, the return is not treated as filed.

Worked example: Rs 8 lakh income, filed 20 October 2026, unpaid tax Rs 12,000

Meera is salaried. Her total income for FY 2025-26 is Rs 8 lakh. Her due date was 31 July 2026, but she files on 20 October 2026 with Rs 12,000 of self-assessment tax still unpaid.

1. Late fee: income of Rs 8 lakh is above Rs 5 lakh → fee = Rs 5,000.
2. Interest: unpaid tax Rs 12,000 × 1% × 3 months (August, September, part-October counted as full) = Rs 360.
3. Total payable: Rs 12,000 (tax) + Rs 5,000 (fee) + Rs 360 (interest) = Rs 17,360.

On the payment screen she will see three separate line items matching these amounts. Had she filed by 31 July, she would have paid only the Rs 12,000 tax.

Frequently asked questions

Can I file ITR after 31 December 2026?

No. The belated-return window closes on 31 December 2026. After that, the only route is an updated return (within 48 months of the end of the assessment year), which carries additional tax of 25% to 60% and cannot be used to claim refunds or carry forward losses.

Can I revise a belated return?

Yes. A belated return can be revised, but only within the same window — by 31 December 2026. The revised return replaces the earlier belated one. So file your belated return early enough to leave time for corrections.

Can I claim deductions in a belated return?

Yes. Every deduction you are genuinely eligible for — 80C, 80D, HRA, standard deduction and so on — can be claimed in a belated return with supporting documents. What you lose is loss carry-forward and (for business income) the tax-regime option, not deductions.

Will I get my refund if I file late?

Yes, refunds are processed for belated returns, but they take longer because they are handled in a later processing batch. E-verify quickly — an unverified return is not processed at all.

Can I file a belated ITR if my income is below the basic exemption limit?

Yes. Filing is worthwhile if TDS was deducted and you want the refund, or if you fall under any mandatory-filing condition (large foreign travel spends, high electricity bills, big deposits, TDS/TCS above Rs 25,000, foreign assets). If no mandatory condition applies and income is below the exemption limit, no late fee is charged.

What happens if I do not file at all?

The department can issue a notice, make a best-judgement assessment of your income, and raise a demand for tax, interest and penalty. In serious cases of wilful non-filing with large tax dues, prosecution is possible. A missing return also leaves your Form 26AS/AIS mismatches unexplained, which invites scrutiny.

Can I switch to the old tax regime in a belated return?

If you have business or professional income, no — opting out of the new tax regime requires Form 10-IEA by the original due date, so a belated return locks you into the new regime for AY 2026-27. If you have no business income, the regime option is chosen in the return itself, but the portal will default you to the new regime — review it carefully before submitting. See our new-regime slabs guide to compare both regimes before you decide.

Official sources

This guide is based on the Income Tax Department’s e-filing portal (incometax.gov.in), CBDT guidance on incometaxindia.gov.in, and the text of the Income-tax Act 2025 on indiacode.nic.in. Rules and due dates can change through CBDT notifications — always verify the current position on the portal before filing.

Disclaimer: This article is general information, not tax advice. Tax rules change through Budget amendments and CBDT notifications. For your specific situation — especially business income, audits, or foreign assets — consult a Chartered Accountant before filing.

Amit Verma

Editorial byline for eircicai freelancer tax and ITR filing guides — covering 44ADA presumptive tax, advance tax, and ITR filing. Content is reviewed by Asuthod Rathod, CA.