Every income tax due date for FY 2026–27, the first year under the Income-tax Act, 2025 — advance tax instalments, return filing dates under section 263, audit reports under section 63, and the interest that applies when you miss one.
Financial year 2026–27 is the first year assessed under the Income-tax Act, 2025, which replaced the Income-tax Act, 1961 with effect from 1 April 2026. The deadlines themselves have largely carried over, but the section numbers behind them have all changed. This calendar gives the date, the provision it comes from, and what it costs to miss it.
One change of vocabulary matters throughout. The 2025 Act drops "previous year" and "assessment year" and uses a single term, tax year. FY 2026–27 is simply tax year 2026-27. Due dates fall in the financial year succeeding the tax year.
Return Filing Due Dates — Section 263(1)
Section 263(1) carries its own table of due dates. These are the dates for the tax year 2026-27, all falling in 2027.
| Who you are | Due date | Falls on |
|---|---|---|
| Any assessee not covered below — most salaried individuals and small businesses | 31st July | 31 July 2027 |
| A company | 31st October | 31 October 2027 |
| A person (other than a company) whose accounts must be audited | 31st October | 31 October 2027 |
| A partner of a firm whose accounts must be audited | 31st October | 31 October 2027 |
| An assessee required to furnish a transfer pricing report under section 172 | 30th November | 30 November 2027 |
Note the fourth row. A partner picks up the firm's 31 October date even where the partner has nothing but salary income of their own — and under the 2025 Act the spouse of such a partner does too, where the clubbing provision in section 10 applies to that spouse.
Advance Tax Instalments — Sections 407 and 408
Advance tax is payable if your estimated liability for the year, after credit for tax deducted at source, is ten thousand rupees or more. The instalment table is unchanged in substance from the old section 211.
| Instalment | Due date | Cumulative amount payable |
|---|---|---|
| First | On or before 15 June 2026 | Not less than 15% of advance tax |
| Second | On or before 15 September 2026 | Not less than 45%, reduced by tax already paid |
| Third | On or before 15 December 2026 | Not less than 75%, reduced by tax already paid |
| Fourth | On or before 15 March 2027 | The whole amount, reduced by tax already paid |
Taxpayers who declare income on a presumptive basis under section 58 pay the entire advance tax in a single instalment on or before 15 March.
What Deferment Costs — Section 425
Section 425 charges interest on the shortfall at each milestone. The rate is 3% on the shortfall at each of the first three instalments and 1% at the fourth.
Worked example. Tax due on returned income is ₹4,00,000. By 15 June you have paid nothing. The 15% milestone is ₹60,000, so the shortfall is ₹60,000 and interest is 3% of that — ₹1,800. If you also miss the 15 September milestone of ₹1,80,000 entirely, interest for that quarter is 3% of ₹1,80,000 — ₹5,400. The charge compounds across milestones, so a single missed first instalment is cheap and a year of neglect is not.
Audit Report — Section 63
Where accounts must be audited, section 63(3) requires the audit report to be furnished by the specified date. Section 63(5)(a) defines that as one month prior to the due date for furnishing the return under section 263(1).
So for a taxpayer whose return is due 31 October 2027, the audit report is due 30 September 2027. The report deadline moves whenever the return deadline moves.
Who Has to Get Audited
Section 63(1) sets the thresholds. A person carrying on business must be audited if turnover exceeds one crore rupees. That threshold rises to ten crore rupees where both of two cash tests are met: cash receipts do not exceed 5% of total receipts, and cash payments do not exceed 5% of total payments. Section 63(2) disapplies the section where profits are declared under the presumptive provisions of section 58(2) or 61(2).
Monthly and Quarterly Obligations
| Obligation | Due date | Provision |
|---|---|---|
| Deposit of tax deducted at source, for April to February | 7th of the following month | Chapter XIX-B |
| Deposit of tax deducted in March | 30 April 2027 | Chapter XIX-B |
| Quarterly statement of tax deducted, quarter ended June | 31 July 2026 | s.397 |
| Quarterly statement, quarter ended September | 31 October 2026 | s.397 |
| Quarterly statement, quarter ended December | 31 January 2027 | s.397 |
| Quarterly statement, quarter ended March | 31 May 2027 | s.397 |
| Certificate of tax deducted from salary, to employees | 15 June 2027 | Chapter XIX-B |
Form numbers are changing, and this guide does not guess at them. Forms are prescribed by the Income-tax Rules, not by the Act. The Rules under the 2025 Act renumber the return, statement and certificate forms that practitioners knew as ITR-1 to ITR-7, 24Q, 26Q, 27Q, 16 and 16A. Confirm the current form number on the e-filing portal before you file, and treat any list of new form numbers you find elsewhere with caution.
Updated Returns — Section 267
If you miss a return or need to correct one, section 267 lets you file an updated return well after the event, on payment of additional income-tax over and above the tax and interest otherwise due. The longer you wait, the more it costs.
| Filed within | Additional income-tax |
|---|---|
| 12 months from the end of the financial year succeeding the tax year | 25% of tax and interest payable |
| After 12 months, before 24 months | 50% |
| After 24 months, before 36 months | 60% |
| After 36 months, before 48 months | 70% |
An updated return cannot be used to report a loss, and cannot be used where it would reduce the total tax liability already determined.
Year-End Actions Before 31 March 2027
- Make any deduction-linked investment or payment you intend to claim under section 123, the successor to section 80C.
- Pay the fourth advance tax instalment by 15 March, not 31 March.
- Reconcile tax deducted against your annual information statement, and take up mismatches with the deductor while the year is still open.
- Close the books, value stock, and record depreciation.
If you are on the new regime, section 123 may be worth little to you. The concessional regime under section 202 disallows most chapter-level deductions in exchange for lower slab rates and a standard deduction of ₹75,000 under section 19. Run both computations before you lock in an investment purely for tax reasons.