Capital gains tax on selling shares

It takes your share of the sale price, less what you paid for your shares and your share of the costs of selling, to find your gain. It then works out the capital gains tax at 2026/27 rates, with Business Asset Disposal Relief if you say you qualify. What you keep is the sale price, less the costs of selling and the tax.

It assumes you're a UK resident individual, that the whole price is paid in cash at completion, and that you have no other gains or losses in the tax year. It applies the £3,000 annual exempt amount once. If you answer Yes to the relief question, it treats your gain as qualifying for BADR, up to your remaining £1m lifetime limit.

If you sell your shares personally, you pay capital gains tax on your gain, not on the whole price. In 2026/27, gains qualifying for Business Asset Disposal Relief are taxed at 18%, up to the £1m lifetime limit. Other gains are taxed at 18% within your unused basic rate band and 24% above it, after the £3,000 annual exempt amount.

No. The tax is charged on your gain, which is the price you receive less what you paid for your shares and the allowable costs of selling. If you founded the company, your base cost is often just the nominal value of your shares, so most of the price can be gain. The calculator works this out for you.

Enter your base cost, which is usually what you paid when you subscribed for or bought the shares. If you founded the company, this is often just the nominal value of the shares you were issued. If your shares came from a reorganisation, a share exchange or a gift, the base cost can be different, so it's worth checking before you rely on the figure.

Your income decides how much of your basic rate band is left for the tax year. Gains that don't qualify for relief are taxed at 18% within that band and 24% above it. Gains qualifying for Business Asset Disposal Relief use up the band first, so on a large sale with relief, your income may make little difference.

The calculator assumes all the price is paid in cash at completion, so it won't be accurate for earn-outs, deferred payments, loan notes or rollover shares. These can change when the gain is taxed and whether relief applies to all of it. Try the earn-out tax timing calculator if part of your price depends on future performance.

It applies the 2026/27 rates and allowances to the figures you enter, so it gives a good indication for a simple cash sale. It isn't advice, and it doesn't check whether you actually meet the Business Asset Disposal Relief conditions. Treat the result as a starting point and have your position reviewed before you agree terms.

No. The calculator runs in your browser, and the figures you enter aren't stored or sent anywhere. If you accept analytics cookies, we record only that the tool was used, not what you entered. You don't need to give your name or email address to use it.

Check that you meet the conditions for Business Asset Disposal Relief for the two years before the sale, and look at how the price will be paid. If anything is unclear, book a call, email taxadvisory@aswatax.co.uk or message +44 7537 143695 on WhatsApp. We reply within one working day, and you'll speak directly with a senior adviser.