How capital gains tax works

Capital Gains Tax (CGT) is charged on the profit when you sell or dispose of an asset that has gone up in value — shares, second homes, rental properties, and most other investments. You only pay CGT on your chargeable gain: the sale proceeds minus the original cost and allowable expenses such as broker fees, legal fees and Stamp Duty.

Each individual has a £3,000 annual exempt amount for 2026/27. The first £3,000 of gains in a tax year are tax-free; anything above that is taxed at 18% or 24%, depending on how much basic-rate income-tax band you have left.

2026/27 CGT rates

RateWhen it applies
18%Gains that fall within your unused basic-rate band
24%Gains above the basic-rate band (higher / additional rate taxpayers)
18% flatBusiness Asset Disposal Relief — qualifying business disposals, £1m lifetime limit

From 6 April 2026 the same 18% / 24% rates apply to residential property and other assets. The old 10% / 20% rates were replaced from 30 October 2024. GOV.UK — Capital Gains Tax rates and allowances · 2026/27

How the 18% and 24% rates are decided

Your other taxable income uses up part of your basic-rate band (£37,700 for 2026/27). Any basic-rate band that remains is where your gains are taxed at 18%; gains above that are taxed at 24%. In practice:

Your taxable incomeChargeable gainTaxable gain (after £3,000)CGT due
£0£10,000£7,000£1,260
£25,000£20,000£17,000£3,318
£60,000£20,000£17,000£4,080

The middle row is a typical shares sale: £50,000 proceeds minus £30,000 costs gives a £20,000 gain. After the £3,000 allowance, £17,000 is taxable. With £25,000 of income, your basic-rate band has £12,700 left, so £12,700 is taxed at 18% (£2,286) and the remaining £4,300 at 24% (£1,032) — total £3,318.

Your main home is usually exempt

Under Private Residence Relief, selling your main home is normally free of CGT. The tax applies to second homes, buy-to-let properties, shares, funds and other investments. If you sell a UK residential property, you generally need to report the gain and pay CGT within 60 days of completion.

Business Asset Disposal Relief

Qualifying business disposals — such as selling all or part of your business — are taxed at a flat 18% in 2026/27 (up from 14% in 2025/26), subject to a £1m lifetime limit. For example, a £100,000 qualifying gain would be taxed at 18% after the £3,000 allowance: £97,000 × 18% = £17,460.

Frequently asked questions

Is my main home exempt from CGT?
Usually yes. Private Residence Relief means your main home is exempt, including the garden up to a limit. CGT applies to second homes, buy-to-let properties and investments held outside tax-free wrappers such as ISAs and pensions.
How do losses affect my CGT?
Losses are deducted from your gains before the annual exempt amount, and unused losses can be carried forward to future tax years. This calculator does not model losses — deduct them from your proceeds first, or enter a reduced gain.
Do I pay CGT on shares inside an ISA?
No. Gains on shares and funds held inside an ISA or pension are completely free of CGT. That is one of the main reasons to hold investments in an ISA — you never use up your £3,000 allowance on them.
What counts as an allowable cost?
The price you paid for the asset plus buying and selling costs such as broker fees, legal fees and Stamp Duty. Money spent on improvements to an asset (for example a property extension) can usually also be deducted before working out your gain.
Educational tools only — not financial advice. Rates and allowances for the 2026/27 tax year, shown as at September 2026. Rules can change — always verify against the latest official guidance.