Section 121 · Losses
Section 121 of the Income-tax Act, 2025 — Filing Your Return on Time to Carry Forward Losses
By CA Rajat Agrawal
Updated 04 Jul 2026
Chapter VII
📜 What the law says — Section 121, Income-tax Act 2025
121. Irrespective of anything contained in this Chapter, no loss which has not been
determined in pursuance of a return filed under section 263(1), shall be
carried forward and set off under section 111(1) or 112(1) or 113(2) or 114(2) or
115(2).
CHAPTER VIII
DEDUCTIONS TO BE MADE IN COMPUTING TOTAL INCOME
A.—General
Deductions to be made in computing total income.
In plain language
What Section 121 actually says
Section 121 of the Income-tax Act, 2025 lays down a simple but powerful rule: if you have incurred a loss in a tax year and you want to carry it forward to set off against future income, you must file your income-tax return by the due date. The loss must be determined in a return filed within the time allowed under Section 263(1) (the return-filing provision of the 2025 Act). If you miss the due date and file a belated return, most losses simply cannot be carried forward — you lose the tax benefit forever for that year.
This provision is the direct successor to Section 80 of the Income-tax Act, 1961. The language has been modernised and the cross-references updated, but the core condition — timely filing is mandatory for carry-forward — is unchanged.
Which losses are covered
The timely-filing condition under Section 121 applies to losses that are eligible to be carried forward under the loss provisions of the Act, namely:
- Business or professional loss (non-speculation) — carried forward up to 8 tax years.
- Speculation business loss — up to 4 tax years.
- Capital losses (short-term and long-term) — up to 8 tax years.
- Loss of a specified business (e.g. certain infrastructure/cold-chain businesses) — carried forward without a fixed year limit, but only against specified-business income.
- Loss from the activity of owning and maintaining race horses — up to 4 tax years.
Important exceptions — losses NOT hit by Section 121
Two categories are outside the reach of Section 121 and can still be carried forward even if you file a belated return:
- Loss from house property — you can still carry it forward (up to 8 years) even with a late return, because it is governed by the house-property set-off provisions, not Section 121.
- Unabsorbed depreciation — treated as current-year depreciation of the next year, it carries forward indefinitely and is not blocked by a late return.
Who it applies to
Section 121 applies to every taxpayer who wants to preserve a loss — individuals, HUFs, firms, LLPs and companies. Salaried individuals rarely trigger it (salary cannot be a loss), but it is critical for traders, investors, business owners and professionals who have loss years.
How it interacts with other sections
- Section 263 fixes the due date and who must file; Section 121 borrows that due date as the deadline.
- The set-off and carry-forward sections (business, speculation, capital, specified-business and race-horse losses) grant the right to carry forward — Section 121 is the gatekeeper that says you only get that right if you filed on time.
- For losses from tax years before 1 April 2026, the transitional rule (Section 536) says they continue to be carried forward under the new Act, but eligibility is judged by the old Act (Section 80 / 139(3)) that applied when the loss arose.
Practical implications
- Never miss the due date in a loss year. Even a one-day delay can wipe out lakhs of rupees of future tax savings.
- Once carried forward correctly, you do not need to re-file in each later year — but you should keep claiming the set-off in each subsequent return.
- A revised return filed within time is fine; a purely belated return is the problem.
- Current-year set-off (adjusting a loss within the same year) is allowed even with a late return — Section 121 only restricts carry-forward to future years.
💡 Example
Example 1 — Trader who filed late. Rohan, an F&O trader, had a non-speculative business loss of ₹6,00,000 in the tax year 2026-27. His due date under Section 263 was 31 July 2027, but he filed on 20 September 2027 (belated). Next year he earns a business profit of ₹9,00,000. Because his return was belated, Section 121 blocks the carry-forward — he cannot set off the ₹6,00,000, and pays tax on the full ₹9,00,000. Had he filed by 31 July 2027, his taxable income would have dropped to ₹3,00,000, saving roughly ₹1,20,000–₹1,80,000 in tax depending on slab.
Example 2 — Investor who filed on time. Meera booked a long-term capital loss of ₹2,50,000 on shares in 2026-27 and filed her return on 15 July 2027 (before the due date). In 2029-30 she makes a long-term capital gain of ₹4,00,000. She validly carries forward and sets off ₹2,50,000, so only ₹1,50,000 is taxed — a clean saving because she respected Section 121.
A relatable story. Two friends, Ajay and Vijay, both lost ₹5 lakh in their small businesses the same year. Ajay treated the July deadline like any other and filed his nil-tax loss return on time. Vijay thought, "I have no tax to pay anyway, why hurry?" and filed in October. Three years later both had good profits — Ajay wiped out his tax using the carried-forward loss, while Vijay watched his ₹5 lakh loss expire uselessly. The only difference between them was a filing date.
| Type of loss | Timely return required to carry forward? | Carry-forward period | Set off against |
|---|
| Business / profession loss (non-speculative) | Yes — Section 121 | 8 tax years | Any business income |
| Speculation business loss | Yes — Section 121 | 4 tax years | Speculation income only |
| Capital loss (STCL / LTCL) | Yes — Section 121 | 8 tax years | Capital gains (LTCL only vs LTCG) |
| Specified business loss | Yes — Section 121 | No fixed limit | Specified-business income only |
| Race-horse activity loss | Yes — Section 121 | 4 tax years | Same activity income only |
| House property loss | No — allowed even if belated | 8 tax years | House property income |
| Unabsorbed depreciation | No — allowed even if belated | Indefinite | Any income (as per rules) |
Related sections
Section 263 — Return of income and due dates Section 111 — Carry forward and set off of business loss Section 112 — Carry forward and set off of capital losses Section 113 — Speculation business loss Section 110 — Set off and carry forward of house property loss Section 536 — Transitional carry forward of pre-2026 losses
Frequently asked questions
If I file my return late, can I still carry forward any loss?
Only house property loss and unabsorbed depreciation survive a belated return. Business, speculation, capital, specified-business and race-horse losses are blocked from carry-forward under Section 121 if the return is not filed by the due date.
Does Section 121 stop me from setting off a loss within the same year?
No. Section 121 only restricts carrying a loss forward to future years. Intra-year set-off against other income of the same year is allowed even if you file late.
What is the due date I must meet?
The due date prescribed under Section 263(1) for your category of taxpayer — commonly 31 July for individuals not subject to audit, and 31 October for audit cases and companies (subject to any Government extension).
I filed a revised return after the due date. Is my carry-forward safe?
Yes, as long as the original return was filed within the due date. A revised return does not lose the benefit; only a purely belated original return does.
Which old-Act section does Section 121 replace?
It corresponds to Section 80 of the Income-tax Act, 1961, which similarly required loss returns to be filed within the Section 139(3) due date to allow carry-forward.
I had a business loss in 2024-25 under the old Act but filed late — can the new Act rescue it?
No. Losses from years before 1 April 2026 are judged under the old Act rules in force then. If Section 80 barred the carry-forward, the 2025 Act does not revive it.
Do I need to file a return every year to keep a validly carried-forward loss alive?
You do not re-establish the loss each year, but you should file returns and claim the set-off in each subsequent year until the loss is fully used or its carry-forward period expires.
C
CA Rajat Agrawal
Chartered Accountant, EaseValue · Reviewed 04 Jul 2026
This explainer is prepared and reviewed by EaseValue's tax team, based on the text of the Income-tax Act, 2025 (as amended by the Finance Act, 2026).
Disclaimer: This page explains the law in general terms for education and is not professional advice. The Income-tax Act, 2025 takes effect from 1 April 2026; provisions, thresholds and interpretations may change. Please confirm your specific position with our team before acting.
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