Short answer: the Income-tax Rules, 2026 (Notification No. 22/2026 dated 20 March 2026) replaced the 1962 Rules from 1 April 2026 — 333 rules and 190 forms, against 511 rules and 399 forms before. Nearly every form number you use routinely has changed, and the old numbers remain correct for old years.
What actually happened
The Act was rewritten; the Rules had to follow. The Income-tax Rules, 1962 had accumulated six decades of amendment, with near-duplicate forms for closely related situations and a long tail of spent provisions.
| 1962 Rules | 2026 Rules | |
|---|---|---|
| Rules | 511 | 333 |
| Forms | 399 | 190 |
| Appendices | — | 3 |
| In force from | 1962 | 1 April 2026 |
Most of the reduction is consolidation rather than removal of obligations. Three property-related challan-cum-statements become one; two declaration forms become one; the TDS quarterly returns keep their function under new numbers.
The form renumbering
This is the part that touches daily work.
| Purpose | Old form | New form |
|---|---|---|
| Salary TDS return (quarterly) | 24Q | 138 |
| Non-salary resident TDS return | 26Q | 140 |
| Non-resident TDS return | 27Q | 143 |
| TCS return | 27EQ | 144 |
| Property / rent / contractor challan-statements | 26QB, 26QC, 26QD | 141 (consolidated) |
| No-deduction declarations | 15G, 15H | 121 (unified) |
| Foreign remittance — declaration and certificate | 15CA, 15CB | 145 / 146 (UDIN-enabled) |
| Relief for salary arrears | 10E | 39 |
| Tax audit report | 3CD | 26 (from TY 2026-27) |
| PAN application | 49A, 49AA | 93–96 |
| TAN application | 49B | 134 / 135 |
| No-PAN declarations | 60, 61 | 97 / 98 |
Two of these deserve a note:
15CB becomes Form 146, and it is UDIN-enabled. The accountant's certificate for a foreign remittance now carries UDIN within the form. For a practice, that changes the issuing workflow, not just the number.
Form 10E becomes Form 39. The relief itself moved from Section 89 to Section 157 of the 2025 Act. Be careful of the neighbour: Section 156 of the 2025 Act is the rebate (the old Section 87A), not arrears relief. Two different reliefs, adjacent numbers, easy to transpose in a working paper.
⚠️ The old forms are still correct — for old years
The single most common error in this transition is applying the new form set to a year that is still governed by the old Act.
| What you are filing | Year | Forms |
|---|---|---|
| Return for FY 2025-26 | AY 2026-27, 1961 Act | Old ITR forms |
| Tax audit for FY 2025-26 | AY 2026-27 | 3CA / 3CB / 3CD, due 30 Sep 2026 |
| Return for FY 2026-27 | Tax year 2026-27, 2025 Act | New form set |
| Tax audit for FY 2026-27 | Tax year 2026-27 | Form 26 |
So the audit season running now is still on the old forms. Form 26 arrives with tax year 2026-27, a year later than most people assume.
Audit thresholds are unchanged by the new Rules — ₹1 crore for business, rising to ₹10 crore where cash receipts and payments are within 5%, and ₹50 lakh for professionals. The Rules renumbered the report; they did not move the trigger. See presumptive taxation under Section 58 for how the audit threshold interacts with the presumptive scheme.
What still works from before
- PAN and TAN remain valid. No reissue is required.
- Existing registrations and approvals granted under the 1962 Rules continue.
- Lower-deduction certificates issued under Section 197 before the transition remain valid for FY 2026-27 receivables.
- Old circulars continue to apply to the extent consistent with the new Act, and govern pre-2026 years outright.
The savings provision at Section 536 of the 2025 Act carries all of this — see pending assessments and appeals after the repeal.
A practical checklist
- Update return templates to Forms 138, 140, 143 and 144 for TY 2026-27 quarters.
- Leave the AY 2026-27 audit on 3CA/3CB/3CD — due 30 September 2026.
- Switch 15CA/15CB workflows to Forms 145/146 and build UDIN into the issuing step.
- Change 10E to Form 39 in your arrears-relief templates, and check you are citing Section 157, not 156.
- Consolidate 26QB/26QC/26QD handling into Form 141.
- Keep old-form templates — they remain correct for old years and will be needed for some time.
For the TDS side in detail, see TDS under Section 393. For the sections behind the forms, the old-to-new mapping is the quick reference.
This is a working reference, not the statute. For anything you are filing or relying on, confirm the current form and rule against the Act, the Rules or the department's official comparison utility.