Income Tax Act 2025 vs 1961: What Actually Changed

On 1 April 2026, India replaced a 65-year-old tax law with the Income Tax Act, 2025. This guide explains every significant change — and, just as importantly, everything that did not change — so you can confidently navigate the transition.

Why was the 1961 Act replaced?

The Income Tax Act, 1961 governed Indian direct taxation from the day it came into force in April 1962 until March 31, 2026. Over 64 years it was amended by every Finance Act, subjected to more than 4,000 individual changes, and expanded from a relatively compact statute to one with over 819 sections — many bearing alphabetic suffixes like 80CCC, 80CCCD(1B), and 234F that reflected emergency insertions rather than logical structure.

The result was a law that was accurate but nearly impossible to navigate without specialist help. The Indian government formed a task force in 2017, which submitted its report in 2019 recommending a complete restructuring. The Income Tax Bill, 2025 was introduced in Lok Sabha on 13 February 2025, passed by both houses, and received Presidential assent on 21 August 2025.

What actually changed

Section numbers

This is the biggest practical change for most taxpayers and tax professionals. Every section of the old Act has been renumbered. The new Act uses sequential numbering without alphabetic suffixes — so instead of Section 80CCD(1B), you now have Section 131(1B). The table below maps the most commonly referenced sections:

Old Section (1961 Act)	New Section (2025 Act)	Subject
Section 80C	Section 123	Investment deductions (ELSS, PPF, LIC, etc.)
Section 80D	Section 124	Medical insurance premium deduction
Section 80CCD(1B)	Section 131(1B)	Additional NPS deduction ₹50,000
Section 44AB	Section 63	Tax audit threshold
Section 44AD	Section 66	Presumptive income for business
Section 44ADA	Section 67	Presumptive income for professionals
Section 87A	Section 87A (retained)	Tax rebate (₹12L zero tax)
Section 192	Section 392	TDS on salary
Section 194A	Section 393	TDS on interest
Section 139	Section 263	Filing of return of income
Section 10	Schedule II	Exempt incomes
Section 24(b)	Section 74	Home loan interest deduction
Section 16	Section 16	Salary deductions (number unchanged)

New terminology

The 2025 Act replaces some long-standing terms to reduce confusion:

Old Term	New Term	Explanation
Previous Year (PY)	Tax Year	The year in which income is earned. Replaces the confusing "previous year" terminology.
Assessment Year (AY)	Assessment Year (retained for transitional use)	The year in which the return is filed and assessed. Gradually being phased out.
Section 10 exemptions	Schedule II	All exempt incomes now listed in a dedicated schedule rather than buried in sub-clauses.

Extended time for updated returns

One substantive change for taxpayers: the window for filing an updated return (ITR-U) has been extended from 24 months to 48 months from the end of the relevant tax year. However, the additional tax surcharge increases the longer you wait — from 25% to 60% of the additional tax payable — so it is still cheaper to file correctly the first time.

What did NOT change

This is equally important. The following aspects remain identical under the 2025 Act:

• Tax rates and slabs — same as introduced in Budget 2025
• New tax regime as the default — you must actively opt for the old regime
• ₹12 lakh zero-tax under new regime — Section 87A rebate unchanged
• ₹75,000 standard deduction — for salaried and pensioners under new regime
• Section 80C (now Sec 123) deduction limit — still ₹1.5 lakh
• Section 80D (now Sec 124) health insurance deduction — unchanged limits
• Five heads of income — Salary, House Property, Business/Profession, Capital Gains, Other Sources
• TDS rates — renumbered but not changed
• Capital gains rates — LTCG at 12.5% and STCG at 20% on equity remain

Digital administration focus

The 2025 Act explicitly modernises the compliance infrastructure. Key changes include a requirement that businesses maintaining electronic books of account must ensure they are accessible from India at all times and that backup servers are physically located in India. This codifies what was previously governed by rules and circulars.

What you should do now

For most taxpayers, the action required is minimal but includes:

1. File FY 2025-26 ITR normally using old 1961 Act sections — due 31 July 2026 (non-audit) or 31 August 2026 (self-employed non-audit under new Act).
2. Learn the new section numbers if you are a CA, tax professional, or actively managing your own taxes. Our Deductions & Exemptions guide maps all major sections.
3. Update your accounting software — most major platforms (Tally, ClearBooks, Zoho Books) have already pushed updates for 2025 Act compliance. Verify your version is current.
4. Check updated return window — if you missed reporting income in a past year, you now have up to 4 years to file an ITR-U (though penalties apply).