Tax Year 2026-27 vs Assessment Year 2026-27 Confusion: Checklist, Due Dates & Common Mistakes
Reviewed by CA Nikhil Gupta · Last reviewed 23 June 2026
It is June 2026, and India has both the old Assessment Year system and the new Tax Year system running simultaneously. If you're filing your ITR in July 2026, you use the old Act and select "AY 2026-27." But if your employer's payroll team references "Tax Year 2026-27," that describes income being earned right now — April 2026 to March 2027. These two "2026-27" labels refer to DIFFERENT income periods, and confusing them is one of the most common mistakes of this transition period. This guide clarifies everything, with a verified due date calendar and 7 common errors to avoid.
The Core Confusion Explained — One Table
The confusion arises because the same "2026-27" appears in both old and new terminology but refers to different income periods. Here is the master mapping:
| Old Act 1961 Term | Income Period | New Act 2025 Equivalent | Your July ITR Action |
|---|---|---|---|
| Financial Year 2025-26 | April 2025 to March 2026 | Tax Year 2025-26 | This is what you earned; file ITR by July 2026 |
| Assessment Year 2026-27 | Refers to FY 2025-26 income (the year you assess it) | Tax Year 2025-26 (same income period, different name) | Select "AY 2026-27" on the portal for your July 2026 ITR |
| Financial Year 2026-27 | April 2026 to March 2027 | Tax Year 2026-27 | Current income year — NOT your July 2026 ITR |
| Assessment Year 2027-28 | Would have referred to FY 2026-27 income under old Act | ABOLISHED — Tax Year 2026-27 replaces both | File ITR for this in July/August 2027 under new Act |
The Conversion Formula — One Rule to Remember
When comparing Assessment Year labels with Tax Year labels, one formula handles everything:
Tax Year N = Assessment Year (N+1) = Financial Year N
Example: Tax Year 2025-26 = Assessment Year 2026-27 = Financial Year 2025-26
Applying this: If someone says "Assessment Year 2026-27," the Tax Year equivalent is Tax Year 2025-26. They are the same income — just labelled differently. If someone says "Tax Year 2026-27," the old-Act equivalent would have been Assessment Year 2027-28. But that old AY label is now abolished.
ITR Due Dates — July 2026 Filing (AY 2026-27, Old Act)
For your current July 2026 ITR filing covering FY 2025-26 income, the official due dates confirmed by CBDT are:
📅 ITR Due Dates — AY 2026-27 (Income from April 2025–March 2026)
What Happens in Parallel — The Overlap Window (April–August 2026)
Between 1 April 2026 and 31 August 2026, two tax systems run simultaneously:
- Filing your AY 2026-27 ITR (old Act): Covering FY 2025-26 income. Old section numbers, old forms (ITR-1 to ITR-7 in old format), old Act rules. Portal Tab 1.
- Earning income in Tax Year 2026-27 (new Act): Your employer is already computing TDS under new section numbers (Section 392(1) not Section 192). The Tax Year started 1 April 2026.
This means your April 2026 salary slip may reference Section 392(1), but your July 2026 ITR for the same employer's TDS from FY 2025-26 will reference Section 192. Both are correct — they apply to different periods.
Case Study: Priya's Confusion — Filing in July 2026 While Earning Under Tax Year 2026-27
Priya received her Form 16 for FY 2025-26 in June 2026. The Form 16 correctly references Section 192 (old Act) for TDS deducted from April 2025 to March 2026. However, her April 2026 payslip shows TDS deducted under "Section 392(1)" — the new Act reference.
- Confusion: Priya's Form 26AS shows TDS for April 2026 under Section 392(1), but her ITR-1 for AY 2026-27 doesn't have a field for "Section 392(1)"
- Resolution: The April 2026 TDS appears in Form 26AS's AY 2027-28 / Tax Year 2026-27 section — not AY 2026-27. She should NOT include April 2026 salary in her AY 2026-27 ITR. Her July 2026 ITR covers only April 2025 to March 2026 income.
- Practical rule: For your July 2026 ITR, use Form 16 (old format) showing income April 2025–March 2026. Your April–June 2026 income belongs in the NEXT filing cycle (Tax Year 2026-27).
7 Common Mistakes to Avoid This ITR Season
🚫 Mistakes Taxpayers Are Making in 2026
- Mistake 1: Selecting "Tax Year 2026-27" instead of "Assessment Year 2026-27" on the e-filing portal for July 2026 ITR — results in filing under the wrong period
- Mistake 2: Including April 2026 salary (Tax Year 2026-27 income) in the AY 2026-27 ITR — that income belongs in next year's filing
- Mistake 3: Confusing belated return and revised return deadlines for AY 2026-27 — the belated return deadline (for missing the 31 July due date) is 31 December 2026; the revised return deadline (to correct a filed return) is 31 March 2027. These are two different deadlines
- Mistake 4: Quoting new Act section numbers (e.g., "Section 123" for 80C) in AY 2026-27 ITR — the old Act applies, cite "Section 80C"
- Mistake 5: Treating Form 121 as applicable for the July 2026 filing — Form 121 replaces 15G/15H from Tax Year 2026-27; for AY 2026-27, Forms 15G/15H still apply
- Mistake 6: Assuming non-audit professionals get until 31 August for ITR-1/ITR-2 — only ITR-3/ITR-4 (non-audit) have 31 August deadline; ITR-1/ITR-2 due date is 31 July
- Mistake 7: Ignoring AIS (Annual Information Statement) for AY 2026-27 — AIS now reflects SGB interest, FD interest, MF redemptions, and capital gains; cross-check before filing to avoid notices
How to Select the Right Portal Tab in July 2026
The income tax e-filing portal (incometax.gov.in) now has two separate sections:
- Tab 1 (Old Act — 1961): For filing AY 2026-27 return (FY 2025-26 income). Use this for your July 2026 ITR. All old section numbers, old forms.
- Tab 2 (New Act — 2025): For Tax Year 2026-27 onwards. Will be used from July/August 2027 for the first Tax Year 2026-27 return.
In July 2026, you will use Tab 1 exclusively. Even though you've been earning income under the new Act since April 2026, that income's ITR will be filed in 2027.
Case Study: CFO Rajesh — Advising Employees on Which Year Label to Use for Loan Applications
Several employees needed ITR and salary documents for home loan applications in May 2026. Banks and home loan officers were asking for "Tax Year" income proof, creating confusion about which year's ITR to provide.
- Bank asked for: "Income proof for Tax Year 2025-26"
- Correct response: Tax Year 2025-26 = FY 2025-26 = AY 2026-27 under old Act. Provide the ITR for AY 2026-27 (which shows FY 2025-26 income). This is the return being filed in July 2026.
- What Rajesh told employees: "When a bank says 'Tax Year 2025-26,' they mean the same income period as what we call FY 2025-26. Your July 2026 ITR (AY 2026-27) shows that income. That's what they want."
- Compliance note for CFOs: Update employee offer letters and income certificates to use consistent terminology. For external stakeholders, consider showing both labels: "Income Tax Return for FY 2025-26 (AY 2026-27 / Tax Year 2025-26)" until the transition settles.
Tax Year vs AY — The Quick Reference Card
- Assessment Year 2026-27 = Tax Year 2025-26 = Income earned April 2025 to March 2026
- Tax Year 2026-27 = Income being earned April 2026 to March 2027 — filed in July/August 2027
- July 2026 ITR: Use "AY 2026-27" on the portal — old Act applies
- Revised return deadline for AY 2026-27: 31 March 2027 (as confirmed by official incometax.gov.in FAQ)
- Belated return deadline for AY 2026-27: 31 December 2026 with late fee
- First Tax Year 2026-27 ITR due: July/August 2027 under new Act
- Conversion formula: Tax Year N = Assessment Year (N+1) = Financial Year N
- BOTH systems run simultaneously April–August 2026 — the overlap window
- Check official dual-system guidance at incometax.gov.in FAQ for the latest CBDT instructions
Related Calculators
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Frequently Asked Questions
Source and review trail
Use the current official instrument, portal or regulator publication before acting. This panel separates the category authority from page-specific references.
- Primary category
- Income Tax
- Official starting point
- www.incometaxindia.gov.in
Page source links
The prior page did not embed a page-specific external source. The category authority above is the minimum verification starting point; a specific instrument should be added when available.
Primary sources & related provisions
Statutory provisions referenced in this guide:
- Form 130 (Certificate under section 395 for tax deducted; earlier Form 16) - Income-tax Forms, 2026
- Form 121 (Declaration under section 393(6) for receipt) - Income-tax Forms, 2026
- Section 392 (Salary and accumulated balance due to an employee; earlier Section 192) - Income-tax Act
- Section 2 (Definitions) - Income-tax Act