For decades, Indian taxpayers had to mentally juggle two overlapping 12-month periods: the 'Previous Year' in which income was earned, and the 'Assessment Year' in which it was taxed. The Income-tax Act, 2025 finally collapses these into a single concept — the 'Tax Year' — starting from income earned in FY 2026-27. Here's exactly what changes, and what doesn't.
Under the Income-tax Act, 1961, if you earned income between 1 April 2025 and 31 March 2026, that period was called the 'Previous Year' (PY 2025-26 or FY 2025-26). You then filed your return in the following year — 1 April 2026 to 31 March 2027 — which was called the 'Assessment Year' (AY 2026-27). So your ITR for income earned in FY 2025-26 is technically 'AY 2026-27's return'.
This dual terminology confused first-time filers every single year — was '2025-26' the year you earned the money, or the year you're filing in? The answer depended on whether you were looking at the Previous Year or the Assessment Year label.
Section 11 of the Income-tax Act, 2025 defines the 'Tax Year' simply as the 12-month period from 1 April to 31 March — the same calendar window as the old Financial Year / Previous Year, but now serving as the sole reference period for earning, computing, and reporting income tax. There is no separate 'assessment year' label running one year ahead.
So income earned between 1 April 2026 and 31 March 2027 will simply be referred to as 'Tax Year 2026-27' — both for the period in which it was earned and as the basis for the return you file (typically by 31 July 2027 for non-audit individual taxpayers, following the existing due-date structure).
| Concept | Old System (1961 Act) | New System (2025 Act) |
|---|---|---|
| Period income is earned | 'Previous Year' (e.g., PY 2026-27) | 'Tax Year 2026-27' |
| Period return is filed/assessed | 'Assessment Year' (e.g., AY 2027-28) | Same 'Tax Year 2026-27' (no separate AY label) |
| Calendar window | 1 April - 31 March | 1 April - 31 March (unchanged) |
| ITR due date for non-audit individuals | 31 July of the following year | Expected to remain 31 July of the following year |
No. This is a terminology and structural simplification, not a change to tax rates, due dates, advance tax schedules, or TDS timing. Advance tax instalments will continue to fall in the same quarters; TDS will continue to be deducted at the time of payment/credit; and the ITR filing deadline structure (31 July for non-audit, 31 October for audit cases, etc.) is expected to be retained — just referenced against the 'Tax Year' rather than separate PY/AY labels.
Beyond reducing first-time-filer confusion, a unified Tax Year also simplifies cross-references throughout the Act. Previously, a provision might say 'income of the previous year relevant to the assessment year' — a phrase that required two definitions to parse. Under the 2025 Act, the same provision can simply reference 'the tax year', cutting down on the explanatory clauses that made the 1961 Act so dense. This is part of the broader ~40% reduction in the Act's overall length.