Capital Gains Tax Basics

Capital Gains on Bonus Shares and Stock Splits: Tax Treatment Explained

10 min read read · Updated 22 February 2026

How Corporate Actions Affect Your Tax

Corporate actions like bonus share issuances and stock splits change the number of shares you hold and potentially the cost basis of each share. While these actions do not create an immediate tax liability (you do not owe tax when receiving bonus shares or when a split occurs), they have significant implications when you eventually sell the shares.

Understanding the tax treatment of bonus shares and stock splits is essential because getting the cost basis wrong can lead to overpaying or underpaying tax, incorrect classification of gains as short-term or long-term, and potential scrutiny from the Income Tax Department.

The two key questions for any corporate action are: 1. What is the cost of acquisition for the new shares? 2. When does the holding period start for the new shares?

For bonus shares, the cost is zero and the holding period starts from the allotment date. For stock splits, the cost is adjusted proportionally and the holding period carries over from the original purchase. These seemingly simple rules have nuances that we will explore with detailed examples.

Other corporate actions like rights issues, mergers, demergers, and buybacks have their own specific tax rules, but bonus shares and stock splits are the most common and affect the largest number of retail investors.

Bonus Shares: Cost Basis Is Zero

When a company issues bonus shares (for example, 1:1 bonus means one free share for every share held), the cost of acquisition for the bonus shares is Rs 0 (zero) under the Income Tax Act.

This has been the settled position since the amendment to Section 55(2)(viia) introduced by the Finance Act 2018 (effective from 1st April 2018). For bonus shares allotted after 1st April 2018, the cost is always zero. For bonus shares allotted before 1st April 2018, the cost is the fair market value on the date of allotment (which was the earlier rule).

The zero cost basis means that when you sell bonus shares, the entire sale price is your capital gain (minus expenses on transfer). This results in a higher taxable gain compared to original shares.

Important clarification: The zero cost applies only to the bonus shares themselves. Your original shares retain their original cost basis. A 1:1 bonus doubles your number of shares, but the original shares still have their original purchase price as the cost basis.

For example, if you held 100 shares bought at Rs 500 each and received a 1:1 bonus of 100 shares: - Original 100 shares: cost remains Rs 500 each - Bonus 100 shares: cost is Rs 0 each - Total shares: 200 - Your total cost basis: 100 x Rs 500 + 100 x Rs 0 = Rs 50,000

Do NOT average the cost to Rs 250 per share across all 200 shares. Each lot has its own distinct cost basis for tax purposes.

Bonus Shares: Holding Period Rules

The holding period for bonus shares starts from the date of allotment of the bonus shares, not from the date you originally purchased the underlying shares. This is a critical distinction.

If you bought shares in January 2024 and received bonus shares in July 2025, the original shares have a holding period starting January 2024, but the bonus shares have a holding period starting July 2025. If you sell in October 2025, the original shares are long-term (held more than 12 months) while the bonus shares are short-term (held about 3 months).

This creates an important FIFO implication. When you sell shares after a bonus issue, FIFO determines which shares are sold first — the original purchases or the bonus shares, based on their respective dates. The original shares (purchased earlier) are deemed sold first under FIFO.

Example: Meera's timeline: - 1st March 2024: Bought 100 shares of XYZ Ltd at Rs 400 each - 1st September 2025: Company issues 1:1 bonus. Meera receives 100 bonus shares. Record date: 1st September 2025. - 1st November 2025: Meera sells 150 shares at Rs 450 each

Under FIFO, the 150 shares sold come from: - 100 original shares (bought 1st March 2024): Holding period = 20 months. This is LTCG. Cost = Rs 400 each. - 50 bonus shares (allotted 1st September 2025): Holding period = 2 months. This is STCG. Cost = Rs 0 each.

The 50 bonus shares sold generate STCG of Rs 22,500 (50 x Rs 450) because their cost is zero.

Bonus Shares: Worked Example with Full Tax Calculation

Let us calculate Meera's complete tax on the sale described above.

From original shares (100 shares, LTCG): - Sale value: 100 x Rs 450 = Rs 45,000 - Cost of acquisition: 100 x Rs 400 = Rs 40,000 - LTCG: Rs 45,000 - Rs 40,000 = Rs 5,000

From bonus shares (50 shares, STCG): - Sale value: 50 x Rs 450 = Rs 22,500 - Cost of acquisition: 50 x Rs 0 = Rs 0 - STCG: Rs 22,500 - Rs 0 = Rs 22,500

Tax calculation: - LTCG of Rs 5,000 is within the Rs 1.25 lakh annual exemption. Tax = Rs 0. - STCG of Rs 22,500 is taxed at 20% = Rs 4,500 - Cess at 4% = Rs 180 - Total tax = Rs 4,680

Notice the sharp contrast: The original shares generated a modest Rs 5,000 LTCG (tax-free). But the bonus shares, despite being sold at the same Rs 450 price, generated Rs 22,500 in fully taxable STCG because their cost basis is zero and they were held for less than 12 months.

Strategy: If possible, hold bonus shares for more than 12 months before selling to convert the gain from STCG (20%) to LTCG (12.5% with exemption). Given the zero cost basis, the tax saving is substantial. On Rs 22,500 gain, waiting would save Rs 4,500 (STCG tax) minus approximately Rs 0 (if within Rs 1.25 lakh LTCG exemption) = Rs 4,500.

Stock Splits: Proportional Cost Adjustment

A stock split changes the face value and number of shares but does not change the total value of your holding or create any taxable event. If a company announces a 1:5 stock split (splitting one share of face value Rs 10 into five shares of face value Rs 2), your total number of shares increases by 5x and the price per share decreases proportionally.

Unlike bonus shares, the cost of acquisition for split shares is adjusted proportionally. Your total cost of acquisition remains the same; it is simply spread across more shares.

Example: You bought 100 shares of ABC Ltd at Rs 2,000 each. Total cost: Rs 2,00,000.

The company announces a 1:5 stock split. After the split: - You now hold 500 shares - Market price adjusts to approximately Rs 400 per share (Rs 2,000 / 5) - Your cost per share: Rs 2,000 / 5 = Rs 400 per share - Total cost remains: 500 x Rs 400 = Rs 2,00,000

The holding period for all 500 shares starts from your original purchase date, not the split date. A stock split does not reset the holding period. If you bought the original 100 shares in January 2024 and the split happened in June 2025, all 500 shares are considered held from January 2024.

This is a fundamental difference from bonus shares: stock splits carry forward both the cost basis (proportionally adjusted) and the holding period from the original shares. Bonus shares have zero cost and a new holding period.

Stock Splits: Worked Example

Raj bought 200 shares of PQR Ltd at Rs 5,000 each on 1st February 2025. Total cost: Rs 10,00,000.

On 1st August 2025, PQR Ltd announces a 1:10 stock split (face value from Rs 10 to Rs 1).

After the split: - Raj holds 2,000 shares (200 x 10) - Cost per share: Rs 5,000 / 10 = Rs 500 per share - Total cost unchanged: Rs 10,00,000 - Holding period starts: 1st February 2025 (original purchase date, not split date)

On 1st March 2026, Raj sells 500 shares at Rs 650 each.

Holding period: 1st February 2025 to 1st March 2026 = 13 months. This is LTCG.

LTCG calculation: - Sale value: 500 x Rs 650 = Rs 3,25,000 - Cost of acquisition: 500 x Rs 500 = Rs 2,50,000 - LTCG: Rs 3,25,000 - Rs 2,50,000 = Rs 75,000 - This is within the Rs 1.25 lakh LTCG exemption. Tax = Rs 0.

If the split had not occurred, Raj would have sold 50 of his original shares (equivalent to the 500 post-split shares) at Rs 6,500 each (10x Rs 650). The math would be identical: - Sale value: 50 x Rs 6,500 = Rs 3,25,000 - Cost: 50 x Rs 5,000 = Rs 2,50,000 - LTCG: Rs 75,000

This confirms that a stock split is economically neutral from a tax perspective. The split changes the number of units and price per unit but not the total gain or holding period.

Bonus vs Stock Split: Tax Comparison

ParameterBonus SharesStock Split
Cost of AcquisitionRs 0 for bonus shares (after April 2018)Original cost divided proportionally
Holding PeriodStarts from allotment date of bonusCarries over from original purchase date
Total Cost Basis ChangeNo change (original cost + Rs 0 bonus)No change (same total, more shares)
FIFO ImpactOriginal shares are sold first (older date)All shares have original purchase date
Immediate Tax EventNo (tax only when sold)No (tax only when sold)
Impact on Future TaxHigher tax due to zero cost basisNeutral — same effective cost per share
STCG RiskYes — new holding period may be short-termNo — holding period carries over

Practical Tips for Managing Corporate Action Tax

Managing the tax implications of corporate actions requires attention to detail and proactive planning.

Keep track of allotment dates for bonus shares. Your broker records should show the bonus allotment date, which becomes the holding period start date for those shares. If you cannot find the exact date, check the company's announcement or your demat statement.

Wait 12 months before selling bonus shares. Given the zero cost basis, bonus shares generate very high capital gains relative to the sale price. Holding for more than 12 months converts this from STCG at 20% to LTCG at 12.5% with the Rs 1.25 lakh exemption, potentially saving significant tax.

Verify your broker's cost basis after corporate actions. Check that your broker has correctly adjusted the cost basis in their tax reports after stock splits and bonus issues. Errors in corporate action processing are not uncommon, especially with less popular brokers.

Understand FIFO interaction. After a bonus issue, FIFO means original shares (earlier date) are sold before bonus shares (later date). This can be advantageous — the original shares may already be long-term, giving you LTCG treatment even soon after the bonus issue. Only after all original shares are exhausted under FIFO would the bonus shares (with zero cost and potentially short-term status) be sold.

For stock splits, simply update your tracking spreadsheet to reflect the new number of shares and adjusted cost per share. No action needed on the holding period since it carries forward unchanged.

Consider gain harvesting on bonus shares after they cross the 12-month mark. Since their cost is zero, the entire sale price is LTCG. Use the Rs 1.25 lakh exemption to sell some bonus shares tax-free each year, gradually reducing the zero-cost-basis risk in your portfolio.

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Frequently Asked Questions

What is the cost of acquisition for bonus shares?

For bonus shares allotted on or after 1st April 2018, the cost of acquisition is Rs 0 (zero). This means when you sell bonus shares, the entire sale price minus transfer expenses is your capital gain. For bonus shares allotted before 1st April 2018, the cost was the fair market value on the date of allotment.

Does the holding period for bonus shares start from the original purchase date?

No. The holding period for bonus shares starts from the date of allotment of the bonus shares, not from when you bought the original shares. This is different from stock splits, where the holding period carries over from the original purchase date. This distinction affects whether your gain is STCG or LTCG.

Is a stock split a taxable event in India?

No. A stock split does not create any immediate tax liability. It simply changes the number of shares and the price per share proportionally while keeping the total value and total cost basis unchanged. Tax arises only when you subsequently sell the shares. The holding period from the original purchase date carries over through the split.

How does FIFO work after receiving bonus shares?

Under FIFO, shares purchased earlier are sold first. After a bonus issue, your original shares (purchased on an earlier date) are sold before the bonus shares (allotted on the bonus date). This often works in your favor because the original shares may already be long-term, qualifying for the lower 12.5% LTCG rate, while the bonus shares with zero cost and a new holding period wait in the queue.

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