ITR 2026 Compliance Calendar: Essential Due Dates Every Assessee Must Track

July traditionally ushers in a peak compliance season under the Income Tax law. During this phase, a wide spectrum of assessees—salaried individuals, pensioners, professionals, businesses, and persons responsible for tax deduction—must monitor several statutory timelines.

These timelines relate to:

  • Payment of Advance tax
  • Filing of income tax returns (ITR)
  • Furnishing tax audit reports
  • Filing belated and revised returns

Failure to adhere to these critical dates can expose an assessee to:

  • Interest under specific sections
  • Late filing fees
  • Possible loss of certain tax benefits (such as carry-forward of losses)
  • General non-compliance risk that may invite scrutiny

Accordingly, advance planning, periodic review of tax position, and close tracking of due dates for Assessment Year (AY) 2026-27 become essential.

Key Compliance Dates for AY 2026-27 at a Glance

Before diving into each date in detail, the important milestones for AY 2026-27 are:

  • Advance Tax Instalments:
    • 15 June, 15 September, 15 December, 15 March
  • Non-audit ITR (Salaried / Non-business):
    • 31 July 2026
  • Certain Non-audit Business/Profession Assessees (ITR-3/ITR-4):
    • 31 August 2026
  • Tax Audit Report:
    • 30 September 2026
  • ITR for Audit Cases:
    • 31 October 2026
  • Belated Return:
    • 31 December 2026
  • Revised Return:
    • 31 March 2027

Each of these has distinct consequences and strategic importance for the assessee.

Advance Tax Instalments – 15 June, 15 September, 15 December, 15 March

Who Needs to Pay Advance Tax?

Advance tax is applicable where the estimated tax liability (after TDS/TCS) crosses the prescribed threshold. Assessees such as:

  • Salaried individuals with significant income from other sources (e.g., interest, capital gains, rental income)
  • Professionals and freelancers
  • Business assessees
  • Senior citizens in certain cases (subject to the specific provisions)

must evaluate their liability and, where applicable, discharge tax on specified instalment dates.

Statutory Due Dates

The standard advance tax instalment schedule is:

  1. 15 June
  2. 15 September
  3. 15 December
  4. 15 March

Non-payment or under-payment by these dates can attract interest under special provisions of the Income Tax Act, 2025 which correspond to interest provisions under the Income Tax Act 1961.

Interest Consequences – Sections 424 and 425

The article refers to sections 424 and 425 of the Income Tax Act, 2025 (corresponding respectively to section 234B and section 234C of the Income Tax Act 1961). The mechanics of interest are as follows:

Interest under Section 424 (corresponding to Section 234B)

Where the aggregate advance tax paid falls below 90% of the assessed tax, interest under Section 424 becomes chargeable.

  • Trigger: Advance tax paid is less than 90% of the assessed tax.
  • Rate: Simple interest at 1% per month or part thereof.
  • Base: Calculated on the shortfall between:
    • Assessed tax, and
    • Advance tax actually paid.

This provision effectively penalizes overall short payment of advance tax across the year.

Interest under Section 425 (corresponding to Section 234C)

Section 425 operates where there is deferment or shortfall in payment of individual advance tax instalments.

  • Trigger: Delay or under-payment in specific due-date instalments (15 June, 15 September, 15 December, 15 March).
  • Rate: Simple interest at 1% per month for the relevant period of delay.
  • Objective: To ensure that tax is paid in a time-bound manner rather than being deferred to the end of the financial year.