Why the Date of the Transaction Decides the Law
Tax liability attaches under the law in force when the transaction occurred, not the law in force when the notice arrives. This is ordinarily invisible, because for most of a practitioner's working life the governing statute does not change. India is now in exactly the period where it does: the Income-tax Act 2025 applies from 1 April 2026, while assessments, appeals and rectifications for earlier years continue to be governed by the Income-tax Act 1961.
The practical difficulty is that the 2025 Act renumbered a great deal of familiar territory without changing its substance. The TDS provisions scattered across Sections 194C, 194J, 194H and 194I now sit within Section 393(1); Section 195 becomes Section 393(2); the interest provisions of Sections 234A, 234B and 234C become Sections 432, 433 and 434; and the new regime under Section 115BAC becomes Section 202. A reply to a notice for FY 2024-25 that cites Section 393(1) is citing a provision that did not exist in the year under assessment.
The same logic applies on the indirect tax side, where the break is older but sharper. GST applies to supplies made on or after 1 July 2017. A transaction before that date falls under the pre-GST framework of central excise, service tax and state VAT, with entirely different classification, credit and limitation rules. Legacy litigation on those years is still moving through the appellate system.
This tool answers the narrow question that matters when you sit down to draft: as at this date, what governed, and what should I cite? It reports the financial year and assessment year the date falls into, identifies the statute in force for both direct and indirect tax, and shows the section mapping oriented the right way round — old numbering for pre-2026 dates, new numbering from 1 April 2026 onwards.
Worked Example: A Contractor Payment on 12 August 2025
A notice raises a TDS default on a payment to a contractor made on 12 August 2025. Establishing which law governed that payment determines how the reply should be framed and cited.
Frequently Asked Questions (FAQs)
From when does the Income-tax Act 2025 actually apply?
From 1 April 2026. Transactions and income arising on or after that date are governed by the 2025 Act and should be cited using its numbering. Everything before it remains under the Income-tax Act 1961, including assessments, appeals, revisions and rectifications for those earlier years that are decided long after the new Act commences.
If I get a notice in 2027 for FY 2024-25, which numbering do I cite?
The 1961 Act numbering, because the year under assessment is governed by the 1961 Act. The date the notice was issued is irrelevant to the question of which statute applied to the income. A reply citing 2025 Act section numbers for a 2024-25 addition is citing provisions that were not in force in the relevant year, and invites an avoidable argument about whether you have engaged with the actual charge.
Did the 2025 Act change the substance of the law or only the numbering?
It is predominantly a consolidation and renumbering exercise rather than a rewriting of substantive liability, which is why a clean old-to-new mapping is possible at all. That said, the mapping is a drafting aid and not a guarantee of identical wording or scope in every case — where a point turns on the precise language of a provision, read the bare text of the Act that actually applies rather than relying on the mapped number.
Why does the tool show both a financial year and an assessment year?
Because notices and orders refer to them inconsistently, and conflating the two is a common source of error. Income earned in the financial year 2025-26 is assessed in the assessment year 2026-27. When a notice cites a year without saying which it means, establishing the financial year from the transaction date is the reliable way to work out what period is actually in issue.
Does this cover changes in GST rates over time?
Not at rate-notification level. The tool identifies which broad regime governed a date — pre-GST indirect tax or GST — but it does not track individual rate changes, exemption withdrawals or circulars over the intervening years. For a rate question on a specific date you will still need the notification history for that HSN or SAC.
Which sections does the mapping cover?
The principal renumbered provisions that arise most often in practice: the TDS chapter, the interest provisions under Sections 234A to 234C and 201(1A), the presumptive taxation sections, the main Chapter VI-A deductions, the new regime, disallowance for delayed payment, and the return-filing provision. It is a working shortlist rather than a complete concordance of the Act.