Income Tax Return Filing Guide: Forms, Due Dates & Documents

Filing your income tax return does not have to be stressful. Here is the whole picture — who files, which form, what documents, by when — in plain language.

Quick answer

An income tax return reports one financial year's income, deductions and tax to the Income Tax Department. For AY 2026-27 — the income of FY 2025-26 — the Income-tax Act, 1961 governs it. ITR-1 and ITR-2 filers are due 31 July 2026, non-audit business and professional cases 31 August 2026, audit cases 31 October 2026. File on the government portal, then e-verify within 30 days.

Who this guide is for

This is written for the person actually doing the filing: a salaried employee with one Form 16 and some interest income, a freelancer deciding between presumptive and regular computation, a proprietor whose turnover crossed a threshold last year, a partner in a firm, or a founder who has to keep a company's ITR consistent with its ROC filings.

It covers AY 2026-27 in detail because that is the year being filed right now. Where a rule has changed, the change is dated. Where a figure depends on facts we cannot see, the guide says so rather than guessing.

The one thing to get straight first

Two different years are live at the same time in 2026, and confusing them is the single most expensive mistake available this year.

Assessment year 2026-27 is the income of FY 2025-26 — 1 April 2025 to 31 March 2026. It is governed entirely by the Income-tax Act, 1961. That remains true even though you are filing after 1 April 2026, and even though the Income-tax Act, 2025 came into force on that date. The Income Tax Department states it directly: the return relates to a year that began before 1 April 2026, and is therefore governed by the old Act.

Tax year 2026-27 is the income of FY 2026-27 — 1 April 2026 to 31 March 2027. That one is governed by the Income-tax Act, 2025, and its return is not due until 2027.

These are two independent obligations, not one obligation described two ways. Both have to be met, each by its own due date. If you are also a deductor, the practical effect shows up in your quarterly statements from April 2026 onward — that transition is covered in the TDS return filing guide.

Who has to file

• Anyone whose income exceeds the basic exemption limit
• Anyone wanting a refund of excess TDS
• Companies, LLPs and firms (mandatory, regardless of profit)
• Those meeting other triggers (foreign assets, high deposits, and so on)

Even when not strictly required, filing builds a record that helps with loans, visas and tenders.

Three of those categories deserve a closer look, because they catch people who assume they are outside the net.

The refund case. If tax was deducted at source and your total income is below the taxable threshold, the only way that money comes back is a filed return. There is no automatic refund. A freelancer who had 10% deducted on ₹6,00,000 of professional fees has ₹60,000 sitting with the government that no one will return unaided.

The loss case. A business or capital loss can be carried forward only if the return declaring it is filed by the due date. File the same loss return a day late and the carry-forward is gone — the tax cost of that lands in a future year, which is why it so often goes unnoticed until it is irreversible.

The foreign-asset case. A resident who holds any asset outside India, has signing authority over any foreign account, or is the beneficiary of a foreign asset must file, regardless of income level. This is also a hard bar on ITR-1 and ITR-4.

Which ITR form

• ITR-1 (Sahaj) — salary, one house property, other income within limits
• ITR-2 — capital gains, multiple properties, no business income
• ITR-3 — business or professional income
• ITR-4 (Sugam) — presumptive business or profession
• ITR-5/6/7 — firms and LLPs, companies, trusts

Picking the wrong form gets the return flagged defective. We choose the right one for your sources.

Here are the eligibility limits the department actually applies for AY 2026-27, which is where most self-filed returns go wrong.

ITR-1 and ITR-4 are both barred if you were a company director at any time in the year, had short-term capital gains, had section 112A long-term gains above ₹1.25 lakh, held any unlisted equity shares at any point, hold any asset or signing authority outside India, have income from any source outside India, have deferred ESOP tax, have any brought-forward or carry-forward loss, or have total income above ₹50 lakh. A single unlisted share from an employer ESOP scheme, or one carried-forward capital loss, moves you off the simple forms entirely.

ITR-4 is optional. The department is explicit that Sugam "is not mandatory" and is used at the assessee's option where they are eligible to declare income on a presumptive basis. Being eligible for presumptive taxation does not oblige you to use it — see the trade-off in ITR filing for freelancers.

Due dates for AY 2026-27

The Finance Act, 2026 rewrote the due-date table with effect from 1 March 2026, so it applies to AY 2026-27. The change is real and widely misreported.

Read the last row carefully. It is the residual category, and it is where a salaried ITR-1 or ITR-2 filer sits. 31 July did not become 31 August for everyone. Only business or professional income moves the date. A salaried employee who also does some consulting has business income and moves to 31 August; a salaried employee with only a savings-account interest credit does not.

Two connected dates matter alongside these:

• The tax audit report for AY 2026-27 is due 30 September 2026 — one month before the 31 October return date. The audit report is a separate filing on Form 3CA or 3CB with Form 3CD, and missing it is its own default. If you are near a threshold, tax audit support is worth scoping early rather than in the last week of September.
• Advance tax runs on instalments through the year itself — the first falling on 15 June and the last on 15 March — with presumptive filers paying the whole liability in a single instalment by 15 March. Getting these wrong costs interest under sections 234B and 234C that no amount of careful filing later can undo — see advance tax payment.

Documents you need

• PAN and Aadhaar (linked)
• Form 16 or income proofs
• Form 26AS and the AIS
• Deduction proofs (80C, 80D, HRA, home loan)
• Bank details for any refund

That is the core list. In practice the set expands with your income sources, and gathering it in the wrong order is what turns a two-hour job into a three-week one.

If you want the list narrowed to your own situation before you start collecting, the ITR document checklist generator builds it from your income sources.

Old vs new regime

The new regime is the default, with lower rates but fewer deductions; the old regime allows deductions at higher rates. Which is lower depends on your deductions — compute both before filing.

For AY 2026-27, the new-regime slabs under section 115BAC(1A) are:

Three details change the arithmetic materially:

• The section 87A rebate ceiling rose to a total income of ₹12,00,000 from AY 2026-27, with the rebate itself capped at ₹60,000 and marginal relief above ₹12 lakh. So a resident individual with total income at or below ₹12 lakh, taxed under the new regime, generally pays nothing. The rebate is not available against special-rate income such as section 111A or 112 capital gains — a point that catches people whose income is mostly from investments.
• The standard deduction against salary is ₹75,000 under the new regime and ₹50,000 under the old. The family-pension deduction is ₹25,000 in the new regime.
• Health and education cess of 4% is added on top of tax and surcharge, with no marginal relief on the cess itself.

The regime choice is not a permanent identity. Someone paying a large home-loan interest and full 80C may still be better off in the old regime; someone with no deductions almost never is. If you carry business income the election rules are stricter and switching is not free every year — old vs new tax regime for business owners sets out the mechanics, and our regime comparison service runs both computations on your actual numbers.

Worked example 1: salaried, new regime

Assumptions. Resident individual, AY 2026-27. Gross salary ₹14,00,000. No other income. Default new regime under section 115BAC. Standard deduction ₹75,000. No chapter VI-A claims. No capital gains.

The rebate is nil because total income exceeds ₹12,00,000. Its marginal-relief limb also gives nothing here: relief only bites where the tax exceeds the amount by which income crosses ₹12 lakh, and ₹78,750 is comfortably below ₹1,25,000.

Against ₹81,900 you set the TDS shown in your Form 16 and any advance tax paid. If your employer deducted ₹85,000, you have a ₹3,100 refund. If they deducted ₹70,000, you owe ₹11,900 as self-assessment tax under section 140A, payable before you file — the portal will not accept the return as complete without it.

Change any assumption and the answer moves. Elect the old regime and you get a ₹50,000 standard deduction but can then claim 80C, 80D, HRA and home-loan interest. Add ₹2,00,000 of listed-equity long-term gains and they are taxed separately at their own rate, outside the slabs and outside the 87A rebate.

Worked example 2: freelancer on presumptive 44ADA

Assumptions. Resident individual professional, AY 2026-27. Gross professional receipts ₹40,00,000, all received by bank transfer. Eligible specified profession. Declaring under section 44ADA. New regime. No other income, no chapter VI-A claims.

Three things follow from choosing 44ADA here. First, no books and no audit are required as long as the declared income is not below 50%. Second, the form is ITR-4, but only because total income is under the ₹50 lakh ITR-4 ceiling — presumptive income of ₹20 lakh clears that, while receipts of ₹40 lakh are irrelevant to the form test. Third, advance tax is due in a single instalment by 15 March, not four.

The trap is on the way out. If actual expenses were high and real profit was ₹12,00,000, declaring that lower figure instead of the deemed ₹20,00,000 triggers a compulsory tax audit under the audit provisions, plus regular books. The presumptive scheme is generous precisely because it removes the audit — you cannot keep the lower profit and the lighter compliance at the same time.

The presumptive ceilings are ₹2 crore of business turnover, or ₹3 crore where cash receipts are 5% or less of turnover; and ₹50 lakh of professional gross receipts, or ₹75 lakh on the same cash test. Section 58 of the Income-tax Act, 2025 restates those figures unchanged for tax year 2026-27, and the department has confirmed the tax audit thresholds — ₹1 crore of business turnover, ₹10 crore on the 5% cash test, ₹50 lakh of professional receipts — carry across from the old Act too.

What it costs

There is no government fee to file an income tax return. Anything you pay to the department is your own tax, interest or a statutory fee — none of it is a filing charge, and none of it should ever be routed through an intermediary.

Keeping those two columns separate is the whole point. A quote that bundles "government fees" into a single number, or that quotes a lower professional fee and recovers it in an unexplained statutory line, is not a cheaper service — it is an unpriced one. Our ITR filing service shows the government amounts and the professional fee as separate lines, computed and explained before anything is paid.

Reconcile, then file

Your return should match your AIS and Form 26AS. Mismatches are the top cause of notices. Reconcile first, file the right form, then e-verify within the window — and you are done.

That sentence is the whole method, but each step has a failure mode worth naming.

Form 26AS is the tax credit statement: TDS, TCS, advance tax, self-assessment tax and refunds. The AIS is broader — it carries reported financial transactions as well: interest, dividends, securities trades, property transactions, large deposits.

Reconcile in this order:

1. Total the TDS in your Form 16 and any Form 16A certificates, and match it against Form 26AS. A gap means the deductor's statement is wrong, not yours.
2. Compare each AIS income line to what you are about to report. Interest from a dormant account and dividend on shares you forgot you owned are the two usual culprits.
3. Where the AIS is wrong, use the feedback facility on the portal rather than silently reporting a different number. An unexplained divergence is what generates the notice.
4. Where a TDS credit is missing, the credit only moves when the deductor files a correction statement. You cannot fix it from your side. Tell them the quarter, the section and the amount.

If a mismatch has already produced a notice, it is usually answerable — see income tax notice reply for what a proper response looks like.

The filing process, step by step

1. Gather and reconcile. Documents in, AIS and 26AS matched, gaps chased before anything is entered.
2. Choose the regime. Compute under both if there is any real chance the old regime wins.
3. Pick the form. Driven by your income sources and by the ITR-1 and ITR-4 disqualifiers, not by which form looks shortest.
4. Compute and pay. Any balance is paid as self-assessment tax under section 140A before filing, with the challan details entered in the return.
5. File. On the official portal, against the correct assessment year — AY 2026-27 for FY 2025-26 income.
6. E-verify within 30 days. Aadhaar OTP, net banking, demat, bank ATM, or a signed ITR-V posted to CPC.
7. Watch for the intimation. A section 143(1) intimation follows processing, showing the department's computation against yours.

E-verification: the 30-day rule

This is the step people treat as a formality, and it is the step that most often converts a compliant return into a late one.

The limit is 30 days from the date of filing. The department's position is precise, and worth stating exactly: where a return is uploaded within the due date but e-verified after 30 days, the date of e-verification is treated as the date of furnishing the return. And where a return is never verified, it is treated as invalid.

The consequences follow mechanically. Upload on 31 July 2026 and verify on 5 September 2026, and your return was furnished on 5 September — a late return, with the section 234F fee, interest under 234A on any unpaid tax, and no carry-forward of that year's business or capital losses. Nothing about the upload date saves it.

If the 30 days have already lapsed, the route is a condonation request on the portal, with a reason. The return is treated as verified only once the department approves it. That is a discretionary outcome, not a formality, which is why it is a poor substitute for verifying on the day you file.

Common mistakes

• Assuming 31 August applies to everyone. It covers non-audit business and professional income and partners of such firms. ITR-1 and ITR-2 filers are still 31 July.
• Treating 31 December as the revision deadline. It is the belated-return deadline and the point after which revising costs a fee. Revision itself runs to 31 March 2027.
• Using ITR-1 or ITR-4 with a disqualifier present — a directorship, unlisted shares, a foreign asset, a carried-forward loss, or income above ₹50 lakh.
• Filing a loss return after the due date, which forfeits the carry-forward.
• Not pre-validating the bank account, so a genuine refund has nowhere to land.
• Reporting a number that contradicts the AIS without using the feedback facility.
• Declaring presumptive income below the deemed rate without accepting the compulsory audit that follows.
• Paying self-assessment tax against the wrong assessment year on the challan — a common and tedious error in 2026, with AY 2026-27 and tax year 2026-27 both selectable.
• Believing the Income-tax Act, 2025 governs this return. It governs tax year 2026-27. AY 2026-27 stays on the 1961 Act.

When a return is treated as defective or invalid

Two different outcomes, often confused.

A defective return under section 139(9) is a filed return the department says is incomplete or internally inconsistent — a missing schedule, a computation that does not tie, an audit case filed without the audit report. You get a notice and a window to correct it. Correct it in time and the return keeps its original date. Ignore it and the return can be treated as invalid, which means never filed.

An invalid return is what an unverified return becomes. There is no notice-and-cure cycle here; the return simply does not exist until a condonation request is approved.

Other reasons a filing goes wrong: a mismatch with AIS or 26AS large enough to trigger an inquiry, presumptive income declared below the deemed rate without the audit, or a refund that cannot be issued because the bank account is not pre-validated.

Penalties, interest and late fees

Filing late attracts a fee under Section 234F and interest under 234A, and you lose the ability to carry forward certain losses. A belated or updated return may still be possible — but on less favourable terms.

How to fix a return you already filed

Four different instruments, four different deadlines. Choosing the wrong one wastes the window on the right one.

Two points about the revised return are genuinely new and worth knowing. The window now runs to the end of the assessment year, not to 31 December — the Finance Act, 2026 extended it, and the stated reason was that revision and belated filing used to expire on the same day, leaving a person who filed belatedly with no opportunity to revise. So a belated return can now be revised, which was not previously possible.

The limb that bites in practice is "or before the completion of the assessment, whichever is earlier". Once your return has been processed and the assessment completed, the right to revise ends, even if 31 March has not arrived. Speed matters more than the calendar here.

An updated return is deliberately one-directional. It cannot produce an enhanced loss, decrease your total tax liability or increase a refund, and only one may be filed per year. It exists to let you report income you left out, not to reclaim tax you overpaid. If a correction would reduce your liability, the revised-return window is the only route — which is another reason not to let it lapse. Where the position is genuinely arguable, revised ITR filing is the service that scopes it.

After filing

Processing produces a section 143(1) intimation — the department's computation set against yours. It may show a refund, a demand, or no change. Read it rather than filing it away: a demand on an intimation is frequently a credit mismatch rather than a real liability, and paying it is the expensive way to close the file.

A refund is credited to the pre-validated bank account linked to your PAN. Refund timing depends on departmental processing and is not something any advisor can promise.

Then look forward. Advance tax for the year you are currently in falls due through the year, not at its end. If you are a deductor as well as a taxpayer, your quarterly obligations continue on their own cycle. And from 1 April 2026 your current-year compliance runs under the Income-tax Act, 2025 — new section numbers on TDS, new forms, advance tax under section 404 — while AY 2026-27 stays on the 1961 Act until it is assessed. Keeping the two years cleanly separated on challans, on the portal and in your records is most of what "staying compliant" means in 2026.

Sources and currency

Applies to: Assessment year 2026-27 (income of financial year 2025-26), India, under the Income-tax Act, 1961

Figures on this page were checked against the primary sources below on 19 August 2026. Due dates, rates and fees change by Finance Act and by notification, and the outcome in any real case depends on your own income and records. Confirm the current position on the income-tax portal before you act.

• Finance Act, 2026 (No. 4 of 2026), s.5 — substitutes Explanation 2 to s.139(1) with the ITR due-date table (31 July / 31 August / 31 October / 30 November) and s.139(5) on revised returns, Gazette of India
• Income Tax Department — returns and forms applicable for AY 2026-27: ITR-1 and ITR-4 eligibility limits and disqualifications
• Income Tax Department — Income Tax Returns FAQs: belated return by 31 December 2026 (s.139(4)), the s.234F fee, and the updated return under s.139(8A)
• Income Tax Department — 30-day time limit to e-verify or submit ITR-V (Notification 2/2024 dated 31.03.2024)
• Memorandum to the Finance Bill, 2025 — s.115BAC(1A) slab rates from AY 2026-27, the enhanced s.87A rebate and the 4% cess; and "Extending the time-limit to file the updated return", which sets the s.139(8A) additional income-tax at 25% up to 12 months, 50% up to 24 months, 60% up to 36 months and 70% up to 48 months from the end of the relevant assessment year
• Memorandum to the Finance (No. 2) Bill, 2024 — standard deduction raised to Rs 75,000 under the new regime
• Income-tax Act, 2025 (No. 30 of 2025) — s.263 (return of income), s.58 (presumptive) and s.63 (audit) for tax year 2026-27 onward, Gazette of India
• Income Tax Department — Income Tax Forms FAQs: tax audit thresholds unchanged, audit report due 30 September 2026 for AY 2026-27