Which return, by when: ITR forms, due dates, advance tax and refunds

What you will learn: which return form fits which situation, the due dates for income of 2025–26 and what happens after them, how advance tax and self-assessment tax work for tax year 2026–27, and how to verify a return and track a refund.

Kavita Rao (an illustrative profile), 45, is a salaried manager in Bengaluru. It is late October 2026. She has not yet filed for 2025–26 because she was waiting for a capital-gains statement, and in August she sold equity fund units at a large long-term gain. A friend says she has "missed the deadline" and also "owes advance tax". Her real question: which form do I use, what deadline still applies to me, and what must I pay before March?

This lesson is the calendar and the forms. How to reconcile records before filing is in Filing well; read that first if you have not.

Two years, two Acts, two sets of forms

Income earned from April 2025 to March 2026 (assessment year 2026–27) is reported in 2026 under the Income-tax Act, 1961, using the ITR forms notified for that year. Income of tax year 2026–27 (April 2026 to March 2027) is reported in 2027 under the Income-tax Act, 2025, on the forms issued for that year, which may carry different names. Use whatever the e-filing portal offers for the year you are filing, not last year's choice.

The supporting documents were renumbered from 1 April 2026 under the Income-tax Rules, 2026:

• the employer's salary TDS certificate is Form 130 (formerly Form 16); for 2025–26 salary you will have received a Form 16;
• the Annual Information Statement is Form 168 (formerly Form 26AS);
• the employee's declaration of rent and deductions to payroll is Form 124 (formerly Form 12BB);
• the nil-tax declaration to a bank is Form 121 (formerly Forms 15G and 15H).

Which form for income of 2025–26

For investors the switch point is usually capital gains. A single short-term sale of shares or fund units, or long-term equity gains above ₹1.25 lakh, moves a salaried person from ITR-1 to ITR-2. Kavita sold some units within a year in 2025–26, so she files ITR-2.

Due dates for 2025–26, and what happens after them

Missing the due date has three costs. A late fee of ₹1,000 where total income is up to ₹5 lakh, and ₹5,000 above that. Interest of 1% a month, or part of a month, on tax still unpaid from the day after the due date. And some reliefs depend on filing on time: losses, for example, have their own timely-filing conditions, covered in Gains, losses and harvesting. From tax year 2026–27, a person without business income chooses the old regime "along with" the return filed under section 263(1), the on-time return, so treat the due date as the last day for that choice too.

Kavita files her belated ITR-2 on 20 November 2026 with ₹18,000 of tax still unpaid. Her fee is ₹5,000, because her income is above ₹5 lakh. Interest runs for August, September, October and part of November, four months: ₹18,000 × 1% × 4 = ₹720. Waiting until December would add another month.

An updated return can still be filed within 48 months of the end of the assessment year, with extra tax, but it cannot reduce tax or increase a refund. For returns of tax year 2026–27, section 263 of the 2025 Act keeps 31 July 2027 as the due date for people with no business income and no audit; check the portal for other categories.

Advance tax: who pays and when

Under section 404 of the 2025 Act, you pay tax during the year if your estimated tax for the year, after TDS and TCS, is ₹10,000 or more. A resident senior citizen (60 or older during the tax year) with no business or professional income does not have to pay advance tax. For a salaried person, employer TDS usually covers the salary; advance tax mostly arises from interest, capital gains, rent or foreign income.

If you declare business or professional profit under a presumptive scheme, the whole amount can be paid by 15 March instead. Two interest charges apply, each simple interest at 1% a month or part of a month:

• Section 425 (deferment): on each shortfall against the cumulative target, for three months (one month for the March instalment). A shortfall caused by a capital gain or other unexpected income is ignored if the tax on it is paid in the remaining instalments.
• Section 424 (default): if less than 90% of the tax is paid by 31 March, from 1 April until you pay.

Business owners will find a worked schedule in Tax for business owners and professionals. Below is the investor's version.

Worked example: Kavita's 2026–27 instalments

Assumptions (illustrative): tax year 2026–27, new regime, resident, salary ₹30 lakh with employer TDS covering the salary tax; fixed-deposit interest ₹1,50,000, taxed at her 30% slab, with ₹15,000 deducted by the bank; equity fund units sold in August 2026 with a long-term gain of ₹4,25,000; 4% cess, no surcharge, no other income.

• Tax on interest: ₹1,50,000 × 30% × 1.04 = ₹46,800.
• Tax on the gain: (₹4,25,000 − ₹1,25,000) × 12.5% × 1.04 = ₹39,000.
• Advance tax for the year: ₹46,800 + ₹39,000 − ₹15,000 TDS = ₹70,800, well above ₹10,000.

In June she knows only about the interest, so 15% of the interest tax net of TDS, ₹31,800 × 15% = ₹4,770, is due. After the August sale, she plans each later instalment on the full ₹70,800:

Adverse case: she pays nothing and settles everything with her return in July 2027. Section 424 interest is about ₹70,800 × 1% × 4 months (April to July) = ₹2,832. Section 425 interest on the missed targets is roughly another ₹3,400 (3% of each of the first three targets, 1% of the last). That is about ₹6,200 for paying late, before the department's rounding rules. Since it is late October 2026, she can still meet the 15 December and 15 March instalments.

Self-assessment tax, e-verification and refunds

Self-assessment tax. Any balance after TDS, TCS and advance tax is paid before you file. When paying online, choose the right tax year and the payment type, advance tax or self-assessment tax; a payment under the wrong year or type creates a mismatch to correct later.

Check Form 168 and the summary. The Annual Information Statement shows TDS, TCS, tax payments, refunds and reported transactions such as interest, dividends and fund sales. Use "Give Feedback" on an entry that is wrong, duplicated or not yours. Report all income you actually earned, even if the statement misses it.

E-verify within 30 days. A return is complete only after verification. If you verify after 30 days, the date of verification is treated as the date of filing, with all the consequences of filing late. A return never verified is treated as invalid.

Refunds. Before filing, pre-validate the bank account for refunds and make sure your PAN is linked to Aadhaar; an inoperative PAN or a closed account makes the refund fail. Track it on the e-filing portal under e-File, Income Tax Returns, View Filed Returns. "Partly adjusted" or "fully adjusted" means the department set the refund against tax it says you owe for another year; check the intimation and respond on the portal if you disagree.

Try this: a six-month tax calendar

1. Confirm whether your 2025–26 return is filed and verified; if not, put 31 December 2026 in your diary.
2. List this year's income outside salary: interest, gains, rent, dividends. Estimate the tax and subtract TDS.
3. If the result is ₹10,000 or more, add 15 December 2026 and 15 March 2027 with amounts beside them.
4. Open your Form 168 now and flag entries to correct before the next return.
5. Pre-validate your refund bank account and check your PAN–Aadhaar link.

Common questions

Where to go next

• Filing well: reconcile records, then submit and verify.
• Interest, distributions and TDS: why TDS is a credit, not the final tax.
• Tax for business owners and professionals: presumptive tax, audit and advance tax.
• Income tax rates for 2026–27: the slab and capital-gains figures used above.
• Further reading: income tax notices and how to respond.