ITR-U updated return: 48-month window and the 25/50/60/70% additional tax slabs

You filed your return on time, paid what the Form 16 said, and moved on. Eight months later you notice a Rs 4,00,000 professional receipt that never made it into the return, or an interest entry sitting in your Annual Information Statement (AIS) that you forgot to report. The revised-return window under Section 139(5) closed on 31 December, the belated-return window is also shut, and yet the income is undeniably yours. This is exactly the gap that the updated return, ITR-U, under Section 139(8A) of the Income Tax Act 1961, was built to close, and from 1 April 2025 the time you have to use it has doubled to 48 months.

The Scenario

Consider Rohan, a salaried product manager who also did Rs 4,00,000 of weekend consulting in FY 2025-26 (Assessment Year 2026-27). His employer deducted TDS on salary, he filed his ITR on 28 July 2026 declaring a total income of Rs 15,00,000, and he genuinely forgot the consulting income because no Form 16A reached him until December 2026. By the time he spots the omission, both the revised-return deadline of 31 December 2026 (Section 139(5)) and the belated-return deadline have passed. His real total income is Rs 19,00,000, not the Rs 15,00,000 he declared.

Rohan's worry is the obvious one: if he stays silent, the entry already sits in his AIS and his Form 26AS reconciliation will eventually flag it, inviting a notice under Section 148A and a far harsher outcome. ITR-U lets him pay the shortfall voluntarily, with a defined additional-tax cost, before the department comes asking. The trade-off he must understand is precise: how much extra he pays depends entirely on how fast he acts after the assessment year ends on 31 March 2027.

Statutory Answer

Section 139(8A) of the Income Tax Act 1961 permits any person, whether or not they filed an original, belated or revised return, to furnish an updated return for a previous year. The Finance Act 2025 extended the filing window from 24 months to 48 months from the end of the relevant assessment year, with effect from 1 April 2025. For AY 2026-27, which ends on 31 March 2027, the outer limit to file ITR-U is therefore 31 March 2031.

The cost of using ITR-U is governed by Section 140B, which charges an additional income-tax over and above the regular tax and interest otherwise payable. The rate is tiered by how late you file, measured from the end of the relevant assessment year:

The base on which these percentages apply is the aggregate of the additional income-tax and the interest (under Sections 234A, 234B and 234C) attributable to the newly disclosed income. The Income Tax Department clarifies the mechanics and the conditions on its ITR-U guidance at incometax.gov.in, and the bare provisions of Sections 139(8A) and 140B are reproduced on indiacode.nic.in.

ITR-U is deliberately fenced in. As the briefing from the Income Tax Department sets out, you cannot use it to reduce a loss, you cannot increase a refund, and you cannot file an updated return that itself reports a loss. It is also barred where a survey under Section 133A, a search under Section 132, a requisition under Section 132A, or notice proceedings have been initiated, or where prosecution proceedings are pending for that year. In short, ITR-U is a one-way street for declaring more income and paying more tax; it is not a tool to claw money back from the exchequer.

Worked Resolution

Take Rohan's AY 2026-27 case through Section 140B step by step, using the FY 2025-26 new-regime slabs (0 to Rs 4,00,000 nil, Rs 4,00,000 to Rs 8,00,000 at 5%, Rs 8,00,000 to Rs 12,00,000 at 10%, Rs 12,00,000 to Rs 16,00,000 at 15%, Rs 16,00,000 to Rs 20,00,000 at 20%). His declared income of Rs 15,00,000 already sits in the 15% slab, so the omitted Rs 4,00,000 is taxed at the margin:

Assume Rohan files his ITR-U 20 months after 31 March 2027, which places him in the 24-month tier at 50%. Interest under Sections 234B and 234C on the Rs 78,000 shortfall accrues at 1% per month; for this illustration take it as Rs 14,000 (the exact figure depends on the precise months of delay, so compute yours against your own filing date). The aggregate base for the Section 140B charge is therefore Rs 78,000 + Rs 14,000 = Rs 92,000.

Applying each tier to that Rs 92,000 base shows why speed matters so much:

In the 24-month tier Rohan actually chooses, his total cash outflow is Rs 78,000 (additional tax including cess) plus Rs 14,000 (interest) plus Rs 46,000 (Section 140B additional income-tax), which comes to Rs 1,38,000. Had he acted within 12 months, the Section 140B layer would have been Rs 23,000 instead of Rs 46,000, saving Rs 23,000 outright. The lesson in the numbers is blunt: every 12 months of delay adds another 10 to 25 percentage points to the additional-tax rate. You can sanity-check the regular-tax portion of any such workings on Oquilia's income tax calculator and confirm which regime is cheaper for your slab using the old vs new regime comparison.

Before you file, three practical checks save grief. First, pay the additional tax and interest as self-assessment tax and quote the challan in the ITR-U, because the return is invalid without proof of payment. Second, run your forward advance-tax estimate for the current year so the same omission does not repeat, using the advance tax calculator. Third, reconcile every AIS and Form 26AS line item first, because ITR-U can be filed only once per assessment year and there is no revising the updated return after submission.

FAQ

Can I file ITR-U if I never filed an original return for that year?

Yes. Section 139(8A) explicitly allows an updated return whether or not you filed an original, belated or revised return for the relevant previous year, provided the 48-month window from the end of the assessment year is still open and none of the bars (search, survey, notice, prosecution) apply. You still pay the Section 140B additional tax on the full liability.

Does ITR-U let me claim a refund I missed?

No. One of the hard limits in Section 139(8A) is that an updated return cannot result in a refund or increase a refund already claimed, and it cannot reduce your total income or convert the return into a loss return. ITR-U only works when the result is additional tax payable. If your correction would generate a refund, ITR-U is not the route.

What is the very last date to file ITR-U for AY 2025-26?

AY 2025-26 ended on 31 March 2026, so under the 48-month window introduced by the Finance Act 2025 the outer deadline is 31 March 2030. Filing in the first 12 months (by 31 March 2027) attracts the lowest 25% additional-tax tier under Section 140B; waiting until the final year pushes it to 70%.

Is the 25% additional tax charged on my whole income or only the new income?

Only on the incremental liability. The Section 140B percentages (25%, 50%, 60% or 70%) apply to the aggregate of the additional income-tax and the interest on the newly disclosed income, not on tax you already paid with the original return. In Rohan's case the base was Rs 92,000, not his entire Rs 19,00,000 income.

Can I file ITR-U after receiving a notice under Section 148A?

No. Section 139(8A) bars an updated return for any assessment year where a notice or proceeding under Section 132, 132A, 133A or 148A has been initiated, or where assessment, reassessment or recomputation is pending. ITR-U is a voluntary, pre-emptive remedy; once the department has formally opened your case, that door closes.

How many times can I file an updated return for the same year?

Only once. Section 139(8A) permits a single updated return per assessment year, and it cannot itself be revised. This is why reconciling your AIS, TIS and Form 26AS completely before filing matters; any second omission discovered later cannot be fixed through another ITR-U for that year.

Will paying through ITR-U protect me from penalty or prosecution?

ITR-U replaces the heavier penalty exposure of an undisclosed-income assessment with the defined Section 140B additional tax of 25% to 70%, which is usually cheaper than penalties under Sections 270A or 271 that can reach 200% of tax on under-reported income. It does not, however, override an already-initiated prosecution; the protection is strongest when you act before any notice lands.