Published 9 May 2026
Understanding the 2026 Shift
One of the most visible changes from 1 April 2026 is the terminology shift. The Income-tax Act, 1961 used 'previous year' (the year of earning) and 'assessment year' (the year of assessment) as a duality. The Income-tax Act, 2025 introduces 'tax year' as the unified concept. This article explains the practical implications -- and why this is more than a cosmetic change.
The Old Framework: Previous Year and Assessment Year
The 1922 Indian Income-tax Act used 'previous year' for the income-earning year and 'assessment year' for the year of assessment. The 1961 Act preserved this language. Pre-Finance Act, 1987, an assessee could even have DIFFERENT previous years for different sources of income -- calendar year for a foreign business, fiscal year for an India business, accounting year for a partnership.
Finance Act, 1987 unified the previous year as the financial year (1 April to 31 March) immediately preceding the assessment year. So under the 1961 Act post-Finance Act, 1987: Previous year 1 April 2024 to 31 March 2025 corresponds to assessment year 2025-26 (1 April 2025 to 31 March 2026). For decades, this two-year language confused taxpayers asking, 'Why am I filing assessment year 2025-26 return for income earned in 2024-25?'
The New Framework: Tax Year
The Income-tax Act, 2025 consolidates the concept into a single 'tax year' equal to the financial year for which tax is computed and the return is filed. So financial year 2026-27 (1 April 2026 to 31 March 2027) is the 'tax year 2026-27' -- and you file your return for that tax year. There is no separate assessment year designation anymore. Income-tax Return forms, tax audit reports, the tax-deducted-at-source framework -- all migrate to tax-year nomenclature for financial year 2026-27 onwards.
Central Board of Direct Taxes-notified Income-tax Return forms for tax year 2026-27 will use the new naming. This is more intuitive and aligns with international tax practice (the United States 'tax year', the United Kingdom 'tax year ended', etc.).
Transition Roadmap: Last Assessment Year Cycle and First Tax Year
Cycle | Period | Terminology | Governing Act |
|---|---|---|---|
Cycle 1 | Financial year 2024-25 | Assessment year 2025-26 (last 'AY' language under old Act) | Income-tax Act, 1961 |
Cycle 2 | Financial year 2025-26 | Assessment year 2026-27 (LAST cycle under old Act) | Income-tax Act, 1961 |
Cycle 3 | Financial year 2026-27 | Tax year 2026-27 (FIRST cycle 'tax year' language) | Income-tax Act, 2025 |
Practical Impact on Filing Calendars
The filing calendar for financial year 2026-27 (tax year 2026-27 under the 2025 Act) sets out as below.
Compliance | Due Date for Tax Year 2026-27 |
|---|---|
Income-tax Return Filing -- Non-audit Individual / Hindu Undivided Family | 31 July 2027 |
Income-tax Return Filing -- Tax Audit Cases | 31 October 2027 |
Income-tax Return Filing -- Transfer Pricing Cases | 30 November 2027 |
Belated Return | 31 December 2027 |
Self-assessment Tax Payment | Before filing return (avoid section 234A interest) |
Updated Return Window | Up to 31 March 2032 (with additional tax 25% to 70%) |
Carry-Forward Position Lock-In
Your assessment year 2025-26 and assessment year 2026-27 returns will determine the carry-forward losses, unabsorbed depreciation, Minimum Alternate Tax credit, and Alternate Minimum Tax credit positions that get carried into the 2025 Act regime starting tax year 2026-27. File these returns CAREFULLY and within the section 139(1) due date. The section 80 condition is strictly enforced; belated returns FORFEIT loss carry-forward (other than house property loss).
Strategy Note Review the loss carry-forward position for each client's assessment year 2025-26 return. Ensure timely filing under section 139(1) due dates. Same discipline for assessment year 2026-27 -- the LAST cycle under the 1961 Act. Once assessment year 2026-27 return is filed, the loss-carry-forward position is locked into the 2025 Act regime. |
Reassessment Time-Limits Under New Framework
Reassessment under section 147 / 148 of the 1961 Act (or section 280 / 281 of the 2025 Act): three years general; ten years for income above INR 50 lakh concealed (per Finance Act, 2021). For tax year 2026-27, reassessment notice can be issued by 31 March 2034 (general) or 31 March 2041 (high-evasion cases).
The transition matters because assessment year 2025-26 reassessment notices issued in 2030 will be under the 1961 Act framework (section 148 plus section 148A pre-notice procedure introduced by Finance Act, 2021), while reassessment notices for tax year 2026-27 issued in 2030 will be under the 2025 Act framework (section 280-281). Practitioners need to know which framework applies for the year being reopened.
What Doesn't Change: Substantive Tax Treatment
Crucially, the tax-year terminology change does NOT affect substantive tax treatment. The income-tax slabs, deductions, exemptions, computation methodology -- all remain as enacted by the applicable Finance Act. Section 87A rebate continues. Section 80C remains for the old regime. Standard deduction INR 75,000 (new regime) / INR 50,000 (old regime) continues. Capital gains rates per Finance Act, 2024 (12.5% long-term capital gains / 20% short-term capital gains on listed equity) are preserved. So while 'tax year 2026-27' replaces 'assessment year 2027-28' in language, your tax computation method does not need to relearn. The change is structural, not substantive.
Key Takeaways
- 'Tax year' replaces previous-year / assessment-year duality from financial year 2026-27 (under the 2025 Act).
- Assessment year 2025-26 plus assessment year 2026-27 -- last two cycles under the 1961 Act with assessment-year language.
- Financial year 2026-27 equals tax year 2026-27 -- the first cycle under the 2025 Act.
- Updated return (Finance Act, 2022 / 2024 No. 2) extends 48 months from the end of the tax year.
- Assessment year 2025-26 and 2026-27 returns lock in carry-forward losses into the 2025 Act regime -- file timely.
- Reassessment time-limit framework continues: three years general / ten years for high-evasion.
- Substantive tax treatment unchanged -- only terminology and structure rationalised.
Disclaimer: This article is for general information only. It does not constitute tax / legal advice. Please consult a qualified Chartered Accountant or tax practitioner for advice specific to your circumstances. The legal position is current as of FA 2024 (No. 2) / FA 2025; subsequent amendments and CBDT notifications may modify the position.