For gains made from April 6, 2026, the UK’s standard Capital Gains Tax rates are 18% within the basic-rate band and 24% above it. The annual tax-free allowance for 2026-27 is £3,000, according to HM Revenue & Customs.

CGT generally applies to taxable profit when an asset is disposed of, not to the full sale price. After deducting the allowance, a basic-rate taxpayer adds the remaining gain to taxable income to see how much fits in the basic-rate band. The portion within that band is taxed at 18%; any excess is taxed at 24%. Higher- and additional-rate taxpayers pay 24% under the standard schedule. HMRC says people do not usually pay CGT when selling their home, though exceptions and separate reliefs apply.

HMRC’s example shows the calculation: with £20,000 taxable income and £12,600 in gains, subtracting the £3,000 allowance leaves £9,600. Combined with income, that is £29,600, below the £37,700 basic-rate band for 2026-27, so the example taxes the gain at 18% (£1,728). A larger gain can cross the band, with only the excess charged at 24%.

A 20 October Guardian report, citing Treasury sources, said the chancellor would not raise CGT in next week’s Budget. That is a reported prospective decision, not enacted law. Check HMRC’s guidance for the asset and reliefs that apply to your circumstances.