Income Tax Act 2025 — Transition from Income-Tax Act 1961 (Effective 1 April 2026): Section-by-Section Mapping + Forms

The Income Tax Act, 1961 stands repealed effective [Fact: it_act_2025_effective_date] per Section 536 of the Income-tax Act, 2025. This is the single biggest structural change in Indian direct-tax law in 60+ years — the 819-section / 14-schedule 1961 Act is replaced by a 536-section / 16-schedule 2025 Act with extensive consolidation, simplification, and new terminology (“Tax Year” replaces “Assessment Year”). This page is the canonical reference for the section-by-section mapping, the transitional rules, and which Act governs which transactions — all primary-source-verified from CBDT’s official “FAQs on Interplay and Transition” document.

The pivot date

Period	Income earned	Governing Act	Assessment terminology
Up to 31 March 2026	FY 2025-26 income	Income-tax Act, 1961	AY 2026-27 (last AY under 1961)
From 1 April 2026	TY 2026-27 income	Income-tax Act, 2025	Tax Year 2026-27 (first TY under 2025)

“Tax Year” under the 2025 Act corresponds to the old “Previous Year” concept under 1961 — it is the year of earning, not the year of assessment. The term Assessment Year is discontinued under the 2025 Act.

Section mapping — verified from CBDT’s transition FAQ

The following mapping is primary-source-verified from the CBDT “FAQs on Interplay and Transition” PDF (cached as evidence, fetched 27 May 2026):

Topic	Old (1961 Act)	New (2025 Act)	Key note
TDS on Salaries	Section 192	Section 392	Salary TDS isolated
TDS on all other non-salary payments (contractor, professional, partner, rent, brokerage, transfer of immovable property, etc.)	Sections 192-194T	Section 393 with 3 tables	All non-salary TDS consolidated
TCS	(various 206C variants)	Section 394	Collection at source consolidated
Foreign payment TDS reporting	Section 195(6)	Section 397(3)(d)	Reporting obligation reframed
Tax audit	Section 44AB	Section 63	Thresholds unchanged (₹1 cr / ₹10 cr business; ₹50 lakh / ₹75 lakh professional)
Presumptive taxation (business + profession)	Sections 44AD / 44ADA	Section 58 (consolidated)	Deemed-profit % unchanged; Section 408(2) for advance tax
Section 80C deductions	Section 80C + Chapter VI-A	Section 123 + Schedule XV	₹1.5 lakh limit unchanged
Section 10 exemptions	Section 10 + sub-sections	Schedule II	Moved from sections to schedule
All deductions	Chapter VI-A	Chapter VIII (Part C specifically)	Consolidated; Section 122(5) makes timely return mandatory

Substantive policy is largely unchanged. The 2025 Act is primarily a structural rewrite — simplification, consolidation, removal of obsolete provisions. Rates, slabs, thresholds, deemed-profit percentages, and deduction limits mostly carry forward identically.

Form mapping — new forms under IT Act 2025

Topic	Old form (1961)	New form (2025)
TDS quarterly statement (non-salary, foreign)	Form 27Q	Form 144
Foreign remittance declaration (declarant)	Form 15CA	Form 145
Foreign remittance CA certificate	Form 15CB	Form 146
Tax audit forms	Form 3CA/3CB + 3CD	(forms applicable to TY 2026-27 onwards per Notification 22/2026; old forms continue for AY 2026-27)
Earlier Form 10AB	Form 10AB	Form 105

Per Notification No. 22/2026, new forms under IT Rules 2026 are live on the e-Filing portal. Access path: e-File → Income Tax Forms → File Income Tax Forms → Forms under Income Tax Act, 2025.

Existing CBDT circulars and rulings under the 1961 Act continue to apply to corresponding provisions in the 2025 Act where intent is unchanged (per CBDT FAQ Q1.21).

TDS section-quoting transition — the system-level pivot

For deductors, the most operationally significant rule:

Transaction date	Section to quote
On or before 31 March 2026	Old section numbers (192, 194C, 194J, 194T, 195, etc.) — under IT Act 1961
On or after 1 April 2026	New section numbers (392, 393, 394) — under IT Act 2025. Quoting old numbers may cause system-level validation errors on the TDS return portal.

For the cross-period TDS return (Q4 FY 2025-26 covering Jan-Mar 2026 transactions): filed under 1961 Act using Form 24Q / 26Q / 27Q / 27EQ, due 31 May 2026. Q1 TY 2026-27 (covering Apr-Jun 2026 transactions): filed under 2025 Act using new forms (Form 144 for foreign TDS), due 31 July 2026.

What this means for your existing FY 2025-26 filing

If you are filing for FY 2025-26 (AY 2026-27) — which is the last AY cycle under the 1961 Act — nothing changes in substance:

• File ITR under IT Act 1961 using existing forms (ITR-1, ITR-2, ITR-3, ITR-4, etc. for AY 2026-27 — published under “Forms as per Income-tax Act, 1961” on the e-Filing portal from 1 April 2026)
• Tax audit report due 30 September 2026 under Form 3CA/3CB + 3CD
• Section references in your return remain 1961 numbering (Section 80C, 80D, 44AB, 194C, etc.)

The transition affects you only from FY 2026-27 onwards (Tax Year 2026-27 in new terminology) — when you’ll use new forms + new section numbers.

The official primary-source utility

CBDT has published an Utility to check provisions of Income-tax Act 1961 vis-à-vis Income-tax Act 2025 on the official ITD portal. For any specific section not covered in the table above, use the utility to find the corresponding section in the new Act. This is the canonical mapping source — secondary-source mapping tables (PwC / KPMG / ClearTax summaries) can be useful for reference but should be verified against the ITD utility for compliance-critical work.

For the full text of the IT Act 2025, see the official Act text on the ITD portal.

How BatchWise positions on the transition

BatchWise does not file ITRs or sign tax-audit reports — that’s the partner CA firm’s role under any of our coordination services. What we do:

• Our content (TDS section pages, tax audit references, etc.) carries the section-mapping callout flagging the IT Act 2025 transition for any reader filing TY 2026-27 onwards
• For ongoing SME compliance subscriptions, the partner CA firm handles the transition seamlessly — Q4 FY 2025-26 TDS returns under the old Act, Q1 TY 2026-27 onwards under the new Act
• Investment declarations + payroll system updates (Section 80C → 123 + Schedule XV) are not our scope but flagged for our SME subscription clients

For specific tax-position advice on the transition (election under new optional schemes, treatment of pending appeals, loss carry-forward across the regime change, transfer pricing implications), engage a CA firm with international-tax + transition-specialist depth directly.