From April 1, 2026, the Income-tax Act, 2025 scraps "Previous Year" and "Assessment Year" and replaces both with one term — Tax Year. Income earned up to March 31, 2026 is still assessed the old way (AY 2026-27). Income earned from April 1, 2026 is simply "Tax Year 2026-27" — no separate assessment-year label. First returns under the new system are filed in 2027.
If you've ever mixed up "Financial Year" and "Assessment Year" on an ITR form, you're not alone — it's one of the most common terminology errors taxpayers and CAs run into every filing season. The Income-tax Act, 2025, which received Presidential assent on August 21, 2025 and takes effect April 1, 2026, fixes this by collapsing the dual-year system into one: the Tax Year.
What's Changing: Assessment Year → Tax Year
Under the outgoing Income-tax Act, 1961, every taxpayer tracked two overlapping 12-month periods:
| Term | Meaning | Example |
|---|---|---|
| Financial Year (FY) / Previous Year | The 12 months in which income is actually earned (Apr 1 – Mar 31) | FY 2025-26 = income earned Apr 2025–Mar 2026 |
| Assessment Year (AY) | The following 12 months, in which that income is assessed and taxed | AY 2026-27 = income from FY 2025-26 is assessed |
The Income-tax Act, 2025 replaces both with a single, continuous 12-month period — the Tax Year — running April 1 to March 31, simply the year income is earned and referenced for tax purposes.
| Old Terminology | New Terminology |
|---|---|
| Previous Year 2026-27 | Tax Year 2026-27 |
| Assessment Year 2027-28 | Removed — replaced by "subsequent tax year" references |
The distinction that trips up most filers: the return for Tax Year 2026-27 income is still physically filed in 2027 — the filing calendar hasn't moved. Only the label on your forms, notices, and the e-filing portal changes.
Why Two Systems Existed — and Why It's Being Scrapped
The FY/AY split dates back to the Income-tax Act, 1961, and has outlived its usefulness for three reasons the government cites directly:
- Filing errors. Wrong-AY selection on ITR forms and challans is one of the most common, entirely avoidable reasons taxpayers get notices.
- MSME compliance burden. Smaller businesses lose time reconciling FY/AY references across TDS and TCS provisions.
- Litigation. Ambiguous cross-references between sections drove disputes that had nothing to do with actual tax owed — just terminology.
This is a simplification exercise, not a tax-policy overhaul. Rates, slabs, and exemptions don't move — only the language and structure around them.
Timeline: Which Law Applies to Which Year
| Period | Governing Law | Terminology |
|---|---|---|
| Up to 31 Mar 2026 (FY 2025-26) | Income-tax Act, 1961 | Financial Year + Assessment Year (AY 2026-27) |
| 1 Apr 2026 onward | Income-tax Act, 2025 | Tax Year 2026-27 onward |
| Filing season, 2027 | Income-tax Act, 2025 | First returns filed for "Tax Year 2026-27" |
Pending assessments, ongoing litigation, and prior-year filings under the 1961 Act carry on exactly as before — the transition is not retroactive.
The Income Tax Act 2025 at a Glance: Other Changes to Note
The Tax Year rename is the most visible change, but the Act restructures several other things you'll run into during FY 2026-27 compliance:
| Area | What Changes |
|---|---|
| Sections | Cut from 800+ to 536 sections across 23 chapters and 16 schedules |
| TDS provisions | Consolidated into a single Section 393, replacing fragmented Sections 192–194T |
| Form 16 | Renumbered Form 130 |
| Form 16A | Renumbered Form 131 |
| Form 26AS | Renumbered Form 168 |
| Form 15G/15H | Renumbered Form 121 |
| Assessments | Digital-first, faceless assessment built into the law to reduce human interface |
| Virtual digital assets | Crypto/NFTs explicitly covered under undisclosed-income provisions where undisclosed |
| Tax slabs | Unchanged — ₹12 lakh basic exemption under the new regime stays as-is |
What This Means for You
| You are… | What to do |
|---|---|
| Salaried individual | Your FY 2025-26 Form 16 still says "Assessment Year 2026-27." Only next year's documents (income from Apr 2026) say "Tax Year 2026-27." See our Form 16 guide → |
| Business / MSME owner | Audit accounting software, invoice templates, and compliance calendars for hard-coded "Assessment Year" references before April 2026. |
| CA / tax professional | Start client education now — the real risk in any terminology switch is confusion, not the underlying computation. |
| Crypto / VDA holder | Review the tightened undisclosed-income rules for virtual digital assets separately — unrelated to the Tax Year change but part of the same Act. See our Crypto tax guide → |
| Capital gains filer | Your STCG/LTCG computation is unaffected by the terminology change. See our STCG/LTCG guide → |
Common Mistakes to Avoid During the Transition
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Don't assume the new Act applies retroactively. Income earned before April 1, 2026 stays under the 1961 Act and the old AY system — full stop.
- Don't discard records labelled "Assessment Year" — they remain valid for audits, litigation, and all prior-year purposes.
- Don't wait until the 2027 filing season to learn the new form numbers (130, 131, 168, 121) — start now.
- Do flag every template, spreadsheet, and software field that hard-codes "AY" for an update before April 2026.
5-Step Checklist to Get Ready
- Map your current AY references across payroll, invoicing, and accounting software.
- Bookmark the renumbered forms — Form 16 → 130, Form 26AS → 168, Form 15G/15H → 121.
- Brief your finance/payroll team on the April 2026 cutover so client- or employee-facing documents don't cause confusion.
- Keep pre-April 2026 records under their original AY labels — don't relabel historical filings.
- Set a reminder for Tax Year 2026-27 filing in 2027 so the new terminology doesn't catch you off guard at filing time.
Key Terms Defined
Tax Year
A single 12-month period, April 1 to March 31, introduced by the Income-tax Act, 2025 to replace both "Previous Year" and "Assessment Year."
Assessment Year (AY)
Under the Income-tax Act, 1961, the 12-month period following the Financial Year in which income earned in that FY is assessed and taxed. Still applies to income earned up to March 31, 2026.
Financial Year (FY) / Previous Year
The 12-month period, April 1 to March 31, in which income is actually earned. Continues to exist as a concept but is no longer paired with a separate Assessment Year from FY 2026-27 onward.
Income-tax Act, 2025
The legislation that repeals the Income-tax Act, 1961. Received Presidential assent on August 21, 2025; effective April 1, 2026. Contains 536 sections across 23 chapters and 16 schedules.
Faceless Assessment
A digital-first assessment process built into the Income-tax Act, 2025 to minimise direct interface between taxpayers and tax officers.
Frequently Asked Questions
What is "Tax Year" under the Income Tax Act 2025?
A single 12-month period from April 1 to March 31 that replaces both "Previous Year" and "Assessment Year" under the Income-tax Act, 1961.
When does the Income Tax Act 2025 come into effect?
It received Presidential assent on August 21, 2025, and comes into force from April 1, 2026, applying from Tax Year 2026-27 onward.
Does Assessment Year still apply to income earned before April 2026?
Yes. Income earned up to March 31, 2026 (FY 2025-26) stays governed by the Income-tax Act, 1961, and is assessed as AY 2026-27 exactly as before.
Will my tax slab or tax rate change because of this Act?
No. Tax rates, slabs, and the ₹12 lakh basic exemption under the new regime are unchanged. This is a structural and terminology simplification, cutting sections from 800+ to 536 across 23 chapters.
When will I file my first return under Tax Year 2026-27?
Returns for Tax Year 2026-27 (income earned April 2026 to March 2027) are filed in 2027 — what would previously have been called Assessment Year 2027-28.
Will Form 16 and Form 26AS get new numbers?
Yes. Under the Income Tax Act 2025, Form 16 becomes Form 130, Form 26AS becomes Form 168, and Form 15G/15H becomes Form 121.
How many sections does the Income Tax Act 2025 have?
The Income-tax Act, 2025 has 536 sections across 23 chapters and 16 schedules, down from over 800 sections in the 1961 Act.
Is this just the Assessment Year renamed, or does anything substantive change?
Largely a rename for timing purposes — the filing calendar doesn't shift — but the Act also consolidates all TDS provisions under one section (393), renumbers key forms, and mandates faceless, digital-first assessment.
Do pending assessments or past tax notices get affected by this change?
No. Pending assessments, ongoing litigation, and prior-year filings under the Income-tax Act, 1961 continue exactly as before; the Tax Year system is not retroactive.
What should businesses do before April 2026?
Audit accounting software, invoicing templates, and compliance calendars for hard-coded "Assessment Year" references and update them ahead of the April 2026 cutover.