Bonus Shares and Stock Splits: Same Excitement, Very Different Tax Maths

Ankit was thrilled when two messages popped up in his broker app. One company had announced a 1:1 bonus issue. Another had declared a stock split. His share count was about to jump in both cases, and that felt like instant wealth. But when Tax season arrived, he realised that bonus shares and stock splits may look similar on the screen, yet their tax treatment is very different.

Take the bonus issue first. Suppose Ankit originally bought 100 shares of a company at Rs 1,000 each. His total cost was Rs 1 lakh. The company then announced a 1:1 bonus, so he received 100 additional shares. After the bonus, the market price usually adjusts downward because the same company value is now spread across more shares. Let us say the stock moves to around Rs 500.

This is where investors often get confused. The original 100 shares still retain their original cost of Rs 1,000 per share. That cost does not get averaged down merely because bonus shares were received. The bonus shares, on the other hand, are generally treated as having nil cost of acquisition. So if Ankit sells the original shares at Rs 500, he may show a capital loss on those shares. But if he sells the bonus shares at Rs 500, almost the full sale value can become taxable gain because the cost is zero. That is why a bonus issue can be tax-disadvantageous in some cases even though it feels like “free shares.” The holding period of the bonus shares is also counted from the date of allotment, not from the date of purchase of the original shares.

Now compare that with a stock split. Suppose Ankit held 100 shares bought at Rs 1,000 each, and the stock splits from Rs 10 face value to Rs 2. He now holds 500 shares. But unlike a bonus issue, there is no new zero-cost asset created. His original total cost of Rs 1 lakh simply gets spread across 500 shares, bringing the cost per share down to Rs 200. In a split, tax does not become tricky because of nil-cost shares; it is largely an exercise in cost apportionment.

So while both bonus issues and stock splits increase your number of shares, they do not work the same way for taxes. A stock split only changes the arithmetic. A bonus issue can create a more uneven tax outcome, because the original shares retain their old cost while the new bonus shares come with nil cost.

That is the real lesson for investors: when corporate actions increase your share count, do not stop at the excitement. Always ask one more question, what happens to the cost base?