Tax Year 2026-27 vs Assessment Year 2026-27 Confusion: Checklist, Due Dates & Common Mistakes
By Finin2min Research DeskP0 — File This FirstUpdated June 2026Live Issue — ITR Season
✅ Verified: incometax.gov.in Official FAQ | Income Tax Act 2025 | CBDT Notifications | ClearTax.in
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.
Use the Income Tax CalculatorModel the tax impact alongside this guide.
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
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The Most Dangerous Mistake: "Tax Year 2026-27" and "Assessment Year 2026-27" sound identical but refer to different income periods. Assessment Year 2026-27 = income earned in FY 2025-26 (file by July 2026). Tax Year 2026-27 = income being earned in FY 2026-27 right now (file by July/August 2027). If you select the wrong year on the ITR portal, you'll file under the wrong period — a defective return requiring revision.
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)
31 Jul 2026
ITR-1 and ITR-2: Salaried individuals (salary + house property + other income sources). Capital gains may require ITR-2. Total income up to ₹50 lakh for ITR-1.
31 Aug 2026
ITR-3 and ITR-4 (non-audit): Self-employed professionals under 44ADA, businesses under 44AD, freelancers with business income not requiring audit.
30 Sep 2026
Tax audit report (Form 3CA/3CB/3CD): Must be filed 1 month before ITR due date for audit cases. Business with turnover above ₹1 crore (or ₹2/10 crore for certain digital cases).
31 Oct 2026
ITR for tax audit cases: Business/professional requiring tax audit under Section 44AB (old Act) / Section 63 (new Act for future years).
30 Nov 2026
Transfer pricing cases: Companies with international transactions requiring Transfer Pricing audit report (Form 3CEB).
31 Dec 2026
Belated return deadline: If you missed the original due date, last chance to file with late fee (₹1,000 or ₹5,000 depending on income). No further extension under old Act.
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Revised Return Update: Under the old Act, revised returns for AY 2026-27 can be filed until 31 December 2026 or before assessment completes. The Income Tax Act, 2025 extends revised return filing to 31 March of the following Tax Year — but this extended deadline only applies from Tax Year 2026-27 (filed in 2027). For AY 2026-27, the old deadline of 31 December 2026 applies.
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
Marketing Manager, Mumbai — Filing ITR for FY 2025-26
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).
July 2026 ITR Covers
April 2025–March 2026
Form to Use
Old ITR-1/ITR-2 (AY 2026-27)
Act Applicable
Income Tax Act, 1961
Tax Year 2026-27 ITR Due
July/August 2027
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
CFO, IT Company, Hyderabad — Employee Home Loan Documentation
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
These two terms refer to DIFFERENT income periods. Assessment Year 2026-27 under the Income Tax Act, 1961 refers to income earned in Financial Year 2025-26 (April 2025 to March 2026). Tax Year 2026-27 under the Income Tax Act, 2025 refers to income earned in FY 2026-27 (April 2026 to March 2027). In plain terms: AY 2026-27 = Income from April 2025 to March 2026, filed July 2026 under old Act. Tax Year 2026-27 = Income from April 2026 to March 2027, filed July/August 2027 under new Act. The conversion formula: Tax Year N = Assessment Year (N+1).
For your July 2026 ITR filing (covering income earned April 2025 to March 2026), you use the Income Tax Act, 1961 — the old Act. Select 'Assessment Year 2026-27' on the e-filing portal. Use ITR-1, ITR-2, ITR-3, or ITR-4 as applicable. Due dates: ITR-1 and ITR-2: 31 July 2026. ITR-3 and ITR-4 non-audit: 31 August 2026. Tax audit cases: 31 October 2026. Transfer pricing: 30 November 2026. The new Tax Year framework applies from your next filing cycle (Tax Year 2026-27 income, filed in July/August 2027).
Yes, for AY 2026-27 specifically. The Income Tax Department's official FAQ confirms the revised return for AY 2026-27 can be filed before 31 March 2027 (or completion of assessment, whichever is earlier). This is governed by old Act Section 139(5). The broader "extended to 31 March of next Tax Year" provision under the new Act applies from Tax Year 2026-27 onwards — but for AY 2026-27, the revised return is also available until 31 March 2027. For belated returns (missing the original July/August 2026 deadline), the last date is 31 December 2026 with late fees of ₹1,000 (income up to ₹5 lakh) or ₹5,000 (higher income). Source: incometax.gov.in Income Tax Returns FAQ (June 2026).