Why every section number changed
The Income-tax Act, 2025 replaced the Income-tax Act, 1961 from 1 April 2026. “Previous year” and “assessment year” became a single tax year (the first is 2026-27), most TDS sections were folded into tables under one section, and the Income-tax Rules, 2026 renumbered the forms. The substance of most provisions carried over — the numbers didn’t.
Old vs new: the most-used sections
| What it covers | 1961 Act | Income-tax Act, 2025 |
|---|---|---|
| Residential status | 6 | 6 |
| Standard deduction (salary) | 16 | 19 |
| Tax audit | 44AB | 63 |
| Presumptive taxation (44AD / 44ADA / 44AE) | 44AD, 44ADA, 44AE | 58 |
| Capital gains exemptions — house / bonds / other assets | 54 / 54EC / 54F | 82 / 85 / 86 |
| Investments deduction (PPF, ELSS, insurance…) | 80C | 123 |
| Health insurance | 80D | 126 |
| Donations | 80G | 133 |
| Startup tax holiday | 80-IAC | 140 |
| Rebate (tax-free up to ₹12 lakh, residents) | 87A | 156 |
| STCG on listed equity / LTCG / LTCG on listed equity | 111A / 112 / 112A | 196 / 197 / 198 |
| Concessional company tax (22%) / new manufacturing (15%) / new regime for individuals | 115BAA / 115BAB / 115BAC | 200 / 201 / 202 |
| Return filing — original / belated / revised / updated | 139(1) / 139(4) / 139(5) / 139(8A) | 263(1) / 263(4) / 263(5) / 263(6) |
| Reassessment | 147 / 148 / 148A | 279 / 280 / 281 |
| TDS on salary | 192 | 392 |
| TDS on payments to residents (194A, 194C, 194H, 194I, 194J, 194Q…) | 194-series | 393(1) — table rows |
| TDS on payments to non-residents | 195 | 393(2) |
| TDS on partner payments, lottery winnings, cash withdrawals | 194T, 194B, 194N | 393(3) |
| Lower / nil TDS certificate | 197 | 395(1) |
| Higher TDS without PAN | 206AA | 397(2) |
| TCS (including LRS remittances) | 206C / 206C(1G) | 394 |
| Advance tax liability / instalments | 207–211 | 403–408 |
| Interest — late return / advance tax default / deferment / late fee | 234A / 234B / 234C / 234F | 423 / 424 / 425 / 428 |
| Penalty for under-reporting | 270A | 439 |
Compiled from published mapping tables and firm analyses; confirm any section you rely on with the official section-mapping tool on the income-tax e-filing portal.
Forms that changed number
| Form | Old | New |
|---|---|---|
| Remittance declaration / CA certificate | 15CA / 15CB | 145 / 146 |
| Transfer pricing report | 3CEB | 48 |
| Treaty relief details | 10F | 41 |
| Lower TDS certificate application | 13 | 128 |
| TDS return for non-residents / certificate | 27Q / 16A | 144 / 131 |
| Tax credit statement | 26AS | 168 |
What it means in practice
- Income earned up to 31 March 2026 (AY 2026-27) is still taxed and filed under the 1961 Act.
- Income from 1 April 2026 falls under the 2025 Act; the first returns under it are filed in 2027.
- Contracts, invoices, board resolutions and TDS returns should quote the new sections from 1 April 2026.
- Rates are covered in the TDS rate chart and the income tax calculator.
Frequently asked questions
What is section 80C called in the Income-tax Act 2025?
Section 123. The deduction for investments such as PPF, ELSS and life insurance continues for those who opt for the old regime.
What replaced section 195 in the Income-tax Act 2025?
Section 393(2), which covers TDS on payments to non-residents through a table of payment types.
When did the Income-tax Act 2025 come into force?
On 1 April 2026. Income from that date is taxed under it; income up to 31 March 2026 is filed under the 1961 Act.
What is section 87A called under the new Act?
Section 156 — the rebate that makes income up to ₹12 lakh tax-free for resident individuals under the new regime.
Please note: this guide is general information based on the rules as they stood on the review date above. Regulations and RBI/CBDT procedures change often — please get advice on your specific facts before acting.