What If You Don't File Your ITR by the Due Date?

The due date for an income tax return is not one deadline with one penalty behind it. It is the trigger for four separate consequences, and they are very unequal in size. The late fee everyone worries about is the smallest of them. The one that costs real money is the one nobody mentions.

The four consequences, in order of how much they cost

1. You lose the carry-forward of losses — permanent

This is the expensive one.

Under Section 80 read with Section 139(1), a business loss and a capital loss can only be carried forward to later years if the return claiming them is filed by the due date under Section 139(1). File one day late and the right is gone. There is no condonation for it in the ordinary course, and a belated return does not restore it.

What that means in practice: a company with a ₹30 lakh business loss this year, that would have set it against next year's profit, loses that shelter entirely. At roughly 25% that is ₹7.5 lakh of tax you will pay in future years that you would not have paid. Against a late fee of a few thousand rupees.

Two important exceptions. Unabsorbed depreciation under Section 32(2) and loss from house property are not subject to this restriction and carry forward even on a belated return. So the damage is confined to business loss and capital loss — which, for a loss-making business, is the whole point.

2. Interest under Sections 234A, 234B and 234C

• 234A — 1% per month or part of a month on the unpaid tax, from the day after the due date to the date of filing. Part months count as full months.
• 234B — 1% per month for shortfall in advance tax, where advance tax paid is less than 90% of the assessed tax.
• 234C — 1% for deferment of the advance tax instalments.

These run on the tax outstanding, so if your tax was fully paid by TDS and advance tax, 234A is nil or negligible. If you owe money, it compounds with every month you wait, which is the argument for filing immediately rather than waiting until the paperwork is perfect.

3. The late fee under Section 234F

A flat fee, charged on filing after the due date:

If your total income is below the basic exemption limit and you were not otherwise required to file, no fee arises.

4. Other knock-on effects

• Refund interest under Section 244A is reduced for the period of your delay.
• Loan and visa applications ask for returns. A missing year is a question you will have to answer, often at an inconvenient moment.
• Tax audit cases — where the audit report is also late, Section 271B comes into play separately. See our post on Section 44AB.
• Section 43B(h) and other provisions keyed to the return due date behave differently, and one of them has no relief at all — see our post on the 45-day MSME rule.

What you can still do

Option 1: a belated return — Section 139(4)

Available up to the end of the relevant assessment year, or before the assessment is completed, whichever is earlier.

A belated return is a full, ordinary return. It carries your refund. It can declare income you had not reported. What it cannot do is carry forward business or capital loss.

File this if you are inside the window. It is the cleanest remedy and the only one that still gets you a refund.

Option 2: an updated return — Section 139(8A), ITR-U

Where the belated window has closed, an updated return can be filed for a longer period following the end of the relevant assessment year — the Finance Act, 2025 extended that period, so check the current limit against the section.

The constraints are significant:

• it cannot declare a loss;
• it cannot reduce your tax liability or increase a refund;
• it cannot be filed where search or survey proceedings are on foot, or in the other cases the section excludes;
• it carries additional tax on top of the tax and interest, at a rate that increases the longer you leave it.

So ITR-U is a way to regularise undeclared income and stop the exposure growing. It is not a way to claim a refund you missed.

Option 3: condonation of delay — Section 119(2)(b)

Where a genuine refund or a loss claim has been lost through a delay that had a real cause — serious illness, a disaster, circumstances outside your control — an application can be made to the Central Board of Direct Taxes or the authority it has empowered, to condone the delay and admit the claim.

This is a discretionary remedy, it needs evidence rather than an explanation, and it takes time. But it is the only route that can restore a loss carry-forward, and it is worth considering where the amount at stake is large.

What if you have not filed for several years?

This is a recoverable position, and it is worth fixing deliberately rather than piecemeal.

1. Establish what the department already knows. Download the Annual Information Statement and Form 26AS for each year. These show the TDS, the high-value transactions, the interest, the securities trades and the property dealings reported against your PAN. You are reconstructing the department's picture of you, which is what any notice will be based on.
2. Check for notices you have missed. Look at the e-filing portal for any notice under Section 142(1) calling for a return, or under Section 148 for income escaping assessment. A pending notice changes the sequence and the options.
3. Work out which years are still open — belated for the current assessment year, ITR-U for the earlier ones within the extended period.
4. File the oldest open year first, so brought-forward figures and tax credits flow correctly.
5. Pay the tax and interest before filing, so 234A stops running.
6. Accept the loss of carry-forward on any loss year that is now out of time, unless the amount justifies a condonation application.
7. Fix the cause. Almost every multi-year default we see traces to books that were never closed. Monthly closing is what prevents this, not a better reminder.

The short version

If you are in profit and your tax is paid, filing late costs you a few thousand rupees and some interest — annoying, not serious. If you are in a loss year, filing late costs you the loss, permanently, and that is often the largest single tax number in the business's life. Treat the due date as immovable in a loss year and negotiable in a profitable one, not the other way round.