Imagine you are reviewing a long-term portfolio for a high-net-worth client who has held legacy shares of a blue-chip company since 2015. As you analyze the tax liability for a potential liquidation, you notice the share price has been volatile, having peaked significantly in early 2018 before correcting. If you only looked at the original cost price, you might overestimate the taxable gain and provide suboptimal advice regarding the client’s net-of-tax proceeds.
The grandfathering mechanism exists precisely to prevent this, ensuring the government does not levy taxes on ‘paper gains’ that evaporated before the current regime took effect.
The logic behind the grandfathering rule is anchored in a comparative cost-basis test. When an investor sells a listed equity share acquired before January 31, 2018, the Income Tax Act allows the investor to substitute the actual cost of acquisition with a ‘deemed cost.’ This deemed cost is the lower of the Fair Market Value (FMV) on January 31, 2018, or the actual sale price.
This calculation ensures that any appreciation in value that occurred before the change in the tax law remains shielded from taxation, effectively creating a tax-neutral floor for the investor.
Consider an investor who purchased shares at Rs. 100 in 2016. By January 31, 2018, the stock rallied to an FMV of Rs. 200, but by the time of the sale, the price dropped to Rs. 150. Under the grandfathering provision, the cost of acquisition is deemed to be Rs. 150 (the lower of the FMV of Rs. 200 and the sale price of Rs. 150). Consequently, the capital gain is zero.
If this mechanism did not exist, the investor would have been liable for tax on a gain of Rs. 50, despite having seen their portfolio value shrink significantly from its 2018 peak.
This calculation is essential for any professional managing client portfolios or conducting rigorous post-tax performance analysis. When building valuation models, failing to account for this ‘step-up’ in cost basis can lead to an artificial inflation of tax expenses in your projections. By accurately applying the grandfathering logic, you refine the net-after-tax returns, which is the only metric that truly matters for long-term wealth preservation. Maintaining precise records of these legacy holdings is a mandatory aspect of compliance and professional advisory standards in the Indian equity markets.
Nuance
Check Your Understanding
An investor bought shares at Rs. 300 in 2017. The FMV on Jan 31, 2018, was Rs. 250. The investor sells the shares in 2024 for Rs. 280. What is the taxable long-term capital gain?
Under Section 112A, which of the following best describes the ‘deemed cost of acquisition’ for shares purchased before January 31, 2018?
This is a companion read for Section 11.2 — Listed Equity Shares from PASS Investment Adviser (Level 2) by Akhilesh Gururani, available on Amazon Kindle.
Copyright © 2026 Akhilesh Gururani. All rights reserved.