When Can Capital Gains Tax Apply to Investments?
Capital Gains Tax can potentially apply when you dispose of an investment and make a gain. Selling an investment is the most familiar type of disposal, although other transactions, such as giving certain investments away, can also count as disposals for Capital Gains Tax purposes.
A rise in the market value of an investment does not normally create a Capital Gains Tax bill by itself. If an investment you bought for £10,000 is now worth £15,000 but you continue to hold it, the £5,000 increase is an unrealised gain. Capital Gains Tax generally becomes relevant when there is a disposal.
Even then, tax is not simply charged on the amount of money you receive. The starting point is normally the gain you have made, after taking account of the investment’s acquisition cost and relevant allowable costs.
This distinction between an investment’s value, its sale proceeds and the gain made on it is fundamental to understanding how Capital Gains Tax works.
What Counts as a Capital Gain?
In a straightforward investment purchase and sale, the gain starts with the difference between what you receive when you dispose of the investment and what it cost you to acquire it. Certain costs associated with buying and selling the investment can also be taken into account.
For shares, for example, allowable costs can include certain broker fees and transaction taxes paid when acquiring them. This means the taxable calculation can be different from simply subtracting the quoted purchase price from the quoted sale price.
Suppose an investor bought an investment for £10,000, has £200 of allowable buying and selling costs and later sells it for £16,000. This is a simplified example. The allowable cost calculation can be more complicated where investments have been acquired in several transactions or other CGT rules apply.From Sale Proceeds to Capital Gain
Calculating the gain is only the first stage. It does not mean that £5,800 would automatically be subject to Capital Gains Tax. Losses, the Annual Exempt Amount and other relevant rules still need to be considered.
Is Capital Gains Tax Charged on the Amount You Sell an Investment For?
One of the most important distinctions in Capital Gains Tax is the difference between sale proceeds and a capital gain.
If you sell £20,000 of investments, you have not necessarily made a £20,000 gain. Part of the money you receive may simply represent the capital you originally invested.
This also means that withdrawing £20,000 from an investment account is not enough information on its own to determine whether Capital Gains Tax is due. What matters is what has been disposed of and the gain arising from that disposal.
Do You Pay Tax When You Sell Investments? looks more closely at what happens when investments are sold and why a sale does not automatically mean that tax is payable.
What Is the Capital Gains Tax Annual Exempt Amount?
Individuals have an Annual Exempt Amount for Capital Gains Tax. For the 2026/27 tax year, this is £3,000.
The exemption applies to your overall Capital Gains Tax position for the tax year rather than giving you a separate £3,000 exemption for every investment you sell. If, after allowable losses and other relevant adjustments, an investor had £8,000 of gains and the full £3,000 Annual Exempt Amount available, £5,000 would remain before considering the applicable Capital Gains Tax rate.
The exemption is therefore one stage of the overall CGT calculation rather than an exemption attached to each individual investment. How the Capital Gains Tax Annual Exempt Amount Works explains how the exemption interacts with multiple gains and losses in more detail.
What Are the Capital Gains Tax Rates on Investments?
For individuals in the 2026/27 tax year, the main Capital Gains Tax rates relevant to investments are 18% and 24%.
The rate applied to a taxable investment gain depends on how that gain sits alongside your taxable income. Gain falling within the available basic-rate band 18% Gain falling above the available basic-rate band 24% Your Income Tax position can affect the Capital Gains Tax rate applied to an investment gain. A single taxable gain can also be divided between the two rates. Rates shown relate to the 2026/27 tax year. Tax rates and rules can change.Main Capital Gains Tax Rates for 2026/27
Lower rate
Higher rate
Knowing the two percentages is therefore not enough to calculate the tax. You also need to establish your taxable income and how much room, if any, remains within the basic-rate band before the taxable gain is considered.
Why Does Your Income Affect the Capital Gains Tax Rate?
Capital gains are not treated as ordinary income, but your taxable income helps determine the rate of Capital Gains Tax charged on taxable gains.
Broadly, you first establish your taxable income. You then consider the taxable gain after the relevant Capital Gains Tax deductions and exemption. The amount of the gain that fits within any remaining basic-rate band can be taxed at the lower CGT rate, while the amount above it can be taxed at the higher rate.
This means being a basic-rate Income Tax payer before making an investment disposal does not necessarily mean that every pound of a large taxable gain will be charged at 18%.
If only a small amount of the basic-rate band remains, part of the gain may use that remaining capacity while the rest is charged at 24%.
Equally, two investors can make the same taxable gain but face different Capital Gains Tax bills because they have different amounts of taxable income.
Can One Gain Be Taxed at Both 18% and 24%?
Yes. A taxable capital gain can cross the boundary between the two CGT rates.
Suppose two investors each have a £10,000 taxable investment gain after the relevant deductions and Annual Exempt Amount have already been considered. One has enough of the basic-rate band remaining for the whole gain, while the other has only £4,000 remaining.
Both simplified examples have a £10,000 taxable gain. The difference is the investor’s taxable income before that gain is considered. This assumes sufficient basic-rate band remains for the entire taxable gain. This assumes only £4,000 of the basic-rate band remains before the taxable gain is considered. The investment gain can be identical while the CGT bill differs. The investor’s taxable income determines how much of the gain can use the lower CGT rate. Simplified examples for 2026/27. Actual CGT calculations depend on the individual’s full circumstances and the type of asset disposed of.The Same Gain Can Produce a Different CGT Bill
Whole Gain Fits Within the Basic-Rate Band
Gain Crosses Into the Higher CGT Rate
In the second example, the £4,000 falling within the remaining basic-rate band produces £720 of CGT at 18%. The remaining £6,000 produces £1,440 at 24%, giving total Capital Gains Tax of £2,160.
How Do Investment Losses Affect Capital Gains Tax?
Not every investment disposal produces a profit. If an investment is disposed of for an allowable capital loss, that loss can potentially reduce gains when working out the overall Capital Gains Tax position.
For example, suppose an investor makes an £8,000 gain on one investment and an allowable £2,000 loss on another. Before considering the Annual Exempt Amount, the two could produce a net gain of £6,000.
If the investor then has the full £3,000 Annual Exempt Amount available, the simplified calculation would leave £3,000 of taxable gains.
Losses can therefore materially change the amount exposed to Capital Gains Tax. However, there are rules governing which losses are allowable, when they can be used and how losses are claimed or carried forward. A fall in the value of an investment you still own is not automatically the same as an allowable capital loss that can be deducted from another gain.
The distinction again comes back to disposal. An investment that has fallen from £10,000 to £7,000 while you continue to hold it has an unrealised loss of £3,000, but that does not by itself mean you can simply deduct £3,000 from another capital gain.
What If You Bought the Same Investment at Different Prices?
The simple examples above assume that identifying the acquisition cost of the investment is straightforward. In practice, investors sometimes buy shares in the same company or units in the same fund on several different dates and at different prices.
For example, you might buy 100 shares at £5, another 100 at £7 and later sell 100 shares at £10. It would be tempting simply to choose one of the purchases and treat those particular shares as the ones that were sold.
UK Capital Gains Tax rules do not always allow the calculation to be approached that way. HMRC has share-identification rules that determine how acquisitions are matched with disposals. These include rules covering purchases made on the same day, certain purchases shortly after a disposal and shares held within a Section 104 holding.
The result is that the allowable acquisition cost used in the CGT calculation may need to be calculated from a pooled holding rather than the price of one particular purchase.
This does not change the underlying principle that CGT is based on the gain rather than the sale proceeds. It does mean that establishing the correct cost of the investment can become more complicated where the same holding has been built through repeated purchases.
Do You Pay Capital Gains Tax on Investments in an ISA?
Capital gains made on investments held within an ISA are not subject to UK Capital Gains Tax. This is one of the main differences between holding an investment within an ISA and holding it in a taxable investment account.
Investment Held Outside an ISA
A disposal at a gain may need to be considered under the Capital Gains Tax rules. Allowable costs, losses, the Annual Exempt Amount, taxable income and the applicable CGT rate can all affect the eventual tax position.
Investment Held Inside an ISA
Capital gains arising on investments held within the ISA are not subject to UK Capital Gains Tax. Those gains do not need to use the £3,000 Annual Exempt Amount.
The ISA changes the UK tax treatment of the investment gain. It does not prevent the investment itself from rising or falling in value.
For example, a £5,000 gain realised on investments within an ISA does not use £5,000 of the investor’s Annual Exempt Amount. The ISA provides separate tax protection for the investments held within it.
The same investment held outside an ISA could have a different tax outcome even if its investment performance were identical. ISA Tax Benefits Explained looks more broadly at the treatment of capital gains, dividends and interest within an ISA.
Are All Investments Subject to Capital Gains Tax?
Not every investment gain is subject to Capital Gains Tax. The type of investment and the account in which it is held can both matter.
As already covered, gains arising from investments held within an ISA are not subject to UK CGT. Certain investments also have their own exemptions. For example, gains on UK government gilts are generally exempt from Capital Gains Tax for individuals, and Qualifying Corporate Bonds have their own CGT treatment.
This means that knowing an investment was sold for more than it cost is not enough to determine whether Capital Gains Tax applies. You first need to identify what was sold and whether the asset itself, or the account containing it, has a relevant exemption.
Where an investment is not exempt, the normal CGT calculation can then become relevant. Selling an investment therefore does not automatically mean that Capital Gains Tax is payable. Whether tax arises depends on the disposal, the gain made and the investor’s wider Capital Gains Tax position. Do You Pay Tax When You Sell Investments? looks specifically at what happens when investments are sold and when a disposal can create a tax consideration.
How to Work Through Capital Gains Tax on an Investment
Rather than starting with the CGT percentage, work through the calculation in sequence.
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Identify the disposal
Establish which investment has been sold, given away or otherwise disposed of and whether the disposal falls within the Capital Gains Tax rules.
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Calculate the gain
Compare the disposal value with the relevant acquisition cost and account for allowable buying, selling or improvement costs where applicable.
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Consider losses and reliefs
Take account of allowable capital losses and any relevant reliefs to establish the gains remaining for the tax year.
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Apply the Annual Exempt Amount
For individuals, the Annual Exempt Amount is £3,000 for 2026/27. Apply the available exemption to the relevant net gains.
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Establish the CGT rate
Consider taxable income and the remaining basic-rate band to establish how much of the taxable gain is charged at 18% and how much, if any, is charged at 24%.
Start with the gain, not the sale proceeds. Capital Gains Tax is calculated only after the investment cost, allowable expenses, relevant losses, exemptions and your wider tax position have been considered.
This is a simplified framework. Particular investments, transactions and personal circumstances can introduce additional Capital Gains Tax rules.
Conclusion
Capital Gains Tax on investments is generally concerned with the gain made when an investment is disposed of rather than the total amount received from the sale. An investment bought for £10,000 and sold for £16,000 has not produced a £16,000 capital gain.
Calculating the initial gain is only the beginning. Allowable costs and losses can affect the amount, individuals have a £3,000 Annual Exempt Amount in 2026/27, and taxable income helps determine whether the remaining taxable gain is charged at 18%, 24% or a combination of the two rates.
The type of investment and where it is held also matter. Gains from investments within an ISA are not subject to UK Capital Gains Tax, while some investments have their own exemptions or special rules. Working through the disposal, gain, losses, exemption and applicable rate in that order provides a clearer way to understand how Capital Gains Tax can apply to investments.
