Mapping Old 1961 Sections to the New Income Tax Act 2025

Income Tax Act 2025 Section Mapping

The Income Tax Act 2025 is now in force. Income earned, TDS deducted and transactions made from April 1, 2026 (Tax Year 2026-27 onwards) fall under the new Act. Returns, assessments and notices for FY 2025-26 (AY 2026-27) and earlier years stay under the 1961 Act. For most taxpayers the rate, slab, and deduction values have not changed. What has changed is the section number under which the rule lives, the chapter where it sits, and the language used to describe it.

This guide is the practical reference for the sections most businesses, professionals, and finance teams use day to day. It pairs the old 1961 section with its corresponding 2025 section and a one-line description of what the section does. For exact section numbers in less common provisions, always confirm against the CBDT concordance table on incometax.gov.in/iec/foportal/.

Why the Renumbering Matters

The 1961 Act grew over six decades through hundreds of amendments. Sections were inserted with letters and decimals (Section 80CCD(1B), Section 194-IA, Section 115BAC, Section 271AAB) and the structure was no longer easy to read. The 2025 Act re-stitches the entire framework so that:

• Each chapter contains all related rules (every TDS rule lives in the same chapter, every deduction lives in another).
• Sub-sections are removed where possible. Long sub-section trees become standalone sections.
• "Previous year" (year of earning) and "assessment year" (year of taxation) collapse into a single tax year.
• "Notwithstanding anything" and double-negative drafting is replaced by direct language.

Rates, slabs, thresholds, and reliefs come from the Income-tax Act, 2025 as amended by the Finance Act 2026. The new Act is structurally simpler, not substantively different.

For the broader picture of what changed, see the Income Tax Act 1961 vs 2025 comparison and the new Income Tax Act 2025 business impact guide.

Tax Year Replaces Previous Year and Assessment Year

This is the single biggest terminology change. Under the 1961 Act, income earned in a "previous year" (for example FY 2025-26) was taxed in the following "assessment year" (AY 2026-27). Under the 2025 Act, the year of earning is simply the tax year, so income earned from 1 April 2026 to 31 March 2027 is Tax Year 2026-27.

Returns for AY 2026-27 (income of FY 2025-26) are filed under the 1961 Act, so the ITR forms, utilities and the e-filing portal still use the AY label for them. The tax year label applies from Tax Year 2026-27 returns, filed in 2027.

Salary, Employment, and Pension

For salary-arrears relief, see the Section 89 relief and Form 10E guide. For perquisites and HRA, see the HRA exemption Section 10(13A) guide.

House Property and Home Loan Interest

The home loan interest deduction continues to apply only under the old tax regime. Under the new regime (the default regime since FY 2023-24), Section 24(b) interest on self-occupied house property cannot be claimed. See the Section 24 home loan interest deduction guide.

Business and Professional Income

For tax audit and Form 3CD reporting, see the Section 44AB guide. For presumptive taxation, see the Section 44AD small business guide and the Section 44ADA professionals guide. For MSME payment compliance, see the Section 43B(h) MSME guide.

Capital Gains

For capital gains exemptions, see the Section 54, 54F, 54EC capital gains exemption guide.

Chapter VI-A Deductions (Sections 80C to 80U)

These deductions remain available only under the old tax regime. Under the new regime, the main deductions still allowed to salaried taxpayers are the standard deduction of Rs 75,000 and the employer NPS contribution under 80CCD(2). For the full 80C list, see the Section 80C deductions list AY 2026-27 guide, and for 80D see the Section 80D health insurance deduction guide.

Section 87A Rebate and the New Tax Regime

For the rebate detail, see the Section 87A rebate AY 2026-27 guide.

TDS and TCS (Now Consolidated Under Section 393)

The 2025 Act moves salary TDS (old Section 192 and 192A) to Section 392, gathers every non-salary TDS rule (old Sections 193 to 195) under a single Section 393, and moves TCS (old Section 206C) to Section 394. Tables inside Section 393 carry the rate, threshold, and applicability for each payment type, and each entry has a four-digit payment code used in challans and TDS returns. Lower or nil deduction certificates (old Section 197) are now under Section 395.

For section-by-section TDS migration steps, see the dedicated TDS and TCS changes for FY 2026-27. For the AY 2026-27 rate chart, see the TDS rate chart 2026 to 2027.

Returns, Assessments, and Refunds

Filing of returns (old Section 139) is now Section 263 of the 2025 Act. It covers the original, belated, revised and updated return. Finance Act 2026 extended the revised return window to 12 months from the end of the tax year, with a fee for revised returns filed after nine months (the same change was made in Section 139(5) and Section 234I of the 1961 Act).

For the AY 2026-27 return deadlines, see the ITR filing last date AY 2026-27 guide.

What This Means for Your Compliance Stack

Five practical items if you have not migrated yet:

1. TDS challans and returns: All Q1 FY 2026-27 TDS deposits and Form 140 must reference the new sub-sections of Section 393. Old codes such as 194C and 194J will be rejected.
2. Employee tax declarations: Form 12BB and salary tax computation worksheets your payroll team uses must be updated. Section 80C, 80D, 24(b), and 10(13A) field labels typically remain unchanged on declarations because they refer to the deduction name, but internal tax computation engines must use the new section numbers.
3. Demand and refund handling: Notices for Tax Year 2026-27 onwards quote 2025 Act sections, while notices for AY 2026-27 and earlier years (for example a Section 148 reassessment notice) continue under the 1961 Act. Always check the year and the Act referenced in the heading.
4. Statutory audit and tax audit reports: Tax audits for FY 2025-26 (AY 2026-27) are reported in Form 3CA/3CB and 3CD under the 1961 Act. From Tax Year 2026-27, the audit report follows the 2025 Act and its new forms. Confirm with your auditor which utility applies to the year being audited.
5. Internal templates and SOPs: Engagement letters, advance tax notes, salary advisories, and disclosure templates that quote section numbers should be reviewed once before the next filing cycle. A search-and-replace exercise is rarely accurate; the section names sometimes change too.

Tax Garden's tax compliance services handle the migration: TDS challan codes, employee tax declarations, software configuration in Tally and Zoho, and the audit walkthrough are all done with the new Act references in place.

Frequently Asked Questions

Why do ITR forms for AY 2026-27 still show 1961 Act section numbers?

Because the income being reported was earned in FY 2025-26, before the Income-tax Act, 2025 took effect on 1 April 2026. Returns for AY 2026-27 are governed by the 1961 Act, so sections such as 80C, 24(b), 87A and 139(1) still apply. The new section numbers will appear in returns for Tax Year 2026-27, filed from 2027.

Where are TDS provisions like 194C and 194J in the new Act?

The Income-tax Act, 2025 consolidates the separate TDS sections of the 1961 Act into a single Section 393, with a table of payment types, rates and thresholds. So payments that were covered by 194C, 194J, 194-I and others are now covered by entries within Section 393 for deductions made from 1 April 2026. Deductions made up to 31 March 2026 keep the old section codes.

Does the section mapping change any tax rates or deduction limits?

No. The mapping only tells you where a rule now sits. Rates and limits come from the Finance Act for each year, and for Tax Year 2026-27 the key individual figures, such as new regime slabs, the Rs 75,000 standard deduction, the Rs 1.5 lakh 80C limit under the old regime and the Rs 12 lakh rebate threshold, are unchanged from FY 2025-26.

Can I use a simple find-and-replace to update old section numbers?

No. The mapping is not one-to-one in every case: some old sections are split into several new ones, some are merged, and some sub-clauses move into schedules. A blanket find-and-replace can also wrongly change references in documents for FY 2025-26 and earlier years, which remain under the 1961 Act. Update references item by item using the official CBDT concordance table.

How should I read an income tax notice received after April 2026?

Check which Act and assessment or tax year the notice refers to. Notices for AY 2026-27 and earlier years continue to be issued under the 1961 Act, since proceedings for those years are saved. Notices for Tax Year 2026-27 onwards cite the 2025 Act. Reply under the Act quoted, and note the response deadline, which is usually stated on the notice itself.

Sources

This guide is verified against the Income Tax Act 2025 as enacted, the Finance Act 2026, the CBDT concordance table published on incometax.gov.in/iec/foportal/, and the practical mapping referenced in the TDS and TCS changes for FY 2026-27. Cross-checked against ClearTax, Tax2win, BajajFinserv, and KDK Software's section-finder coverage of the 2025 Act as of May 2026. For exact new section numbers in less common provisions (international tax, transfer pricing, search and seizure, settlement commission), always confirm against the official CBDT notification before quoting in a contract or filing.