Reassessment After 1 April 2026: Old Section 148 vs New Sections 279–286, With Transition Examples

Finin2min 2-Minute Summary

• Reassessment for Tax Year 2026-27 and later falls under the Income Tax Act, 2025 framework, while earlier years remain governed by the preserved old Act.
• The Department’s FAQ says fresh earlier-year reassessments can still be initiated after 1 April 2026 under the old law where its conditions are met.
• A notice sequence already initiated under old section 148A continues under the old Act.
• Parallel proceedings under old and new Acts can coexist for different income periods.

What the rule means in practice

The practical risk is a hybrid response that quotes old notice numbers but new-Act time limits, or vice versa. Start every reassessment file with a one-page “governing law” note that records the income period, notice chain and section map.

Parallel old/new proceedings are possible because the tax periods differ. Document-management systems should include the assessment year/tax year in filenames and matter IDs. That small control reduces the risk of uploading the wrong return computation, reply or case-law bundle to the wrong proceeding.

Worked example

Professional analysis

Reassessment is one of the areas where the dual-Act transition is easiest to misread. The official FAQ separates Tax Year 2026-27 and later, which use the new reassessment provisions, from earlier periods that remain within the preserved 1961 Act framework. The year being reopened therefore controls the legal route even when the notice is received after April 2026.

Legacy proceedings should keep their original statutory history intact. If a section 148A process began under the old law, the file should preserve the notice, response, order and subsequent section 148 notice in sequence. Replacing those references with the new section numbers can distort limitation and procedural arguments.

A taxpayer can encounter old-law and new-law reassessment activity at the same time for different periods. The notice register should consequently carry separate columns for income period, governing Act, notice section, service date and response deadline. That simple split prevents a response prepared for one framework from being reused in the other.

Edge cases and records to preserve

Search, survey or information-based reassessment files often contain evidence gathered at different dates. Keep a chronology showing when the department obtained the information, when the taxpayer was asked to respond and which statutory provision governed each step. This can matter to both limitation and procedural fairness. A single folder labelled “reassessment 2026” is not enough when more than one tax regime is involved.

For Tax Year 2026-27 onward, teams should build new templates directly from sections 279–286 instead of mechanically renumbering old section 148 material. For earlier years, preserve the old notice language and jurisprudence relevant to that regime. The two libraries can coexist, but they should not be blended into one generic notice-response precedent.

Implementation notes

A reassessment dashboard should separate jurisdictional objections from merits. One column can track limitation, information source, notice sequence and statutory compliance; another can track the income addition, evidence and computation. This prevents a strong procedural objection from causing the merits file to be neglected, and it prevents a good merits explanation from waiving a threshold objection inadvertently. Responses can then reserve legal rights while still supplying factual material where appropriate. The dashboard should also flag whether an old-year matter is already in appeal or another proceeding that affects the reassessment narrative.

Additional control point

Document retention should follow the proceeding rather than the financial-year folder alone. Create one indexed set containing the original return, computation, notice material, information relied upon where disclosed, taxpayer responses and every order generated during reassessment. Cross-reference connected assessment or appellate matters. This makes it possible to test whether the same item is being examined in more than one proceeding and whether an explanation previously supplied needs to be carried forward, distinguished or corrected.

Frequently asked questions

Which law applies to reassessment of AY 2024-25 after April 2026?

The Income Tax Department FAQ says earlier tax years continue under the old Act.

When do new sections 279–286 apply?

They apply to Tax Year 2026-27 and subsequent tax years according to the official FAQ.

Can old and new reassessments run at the same time?

Proceedings under the two Acts can coexist for different income periods.

Official sources

• Income Tax Department — Reassessment Proceedings FAQs — Sections 279–286 / section 536 transition.