Capital gains tax catches many UK investors and property sellers by surprise. Understanding how it works — and the allowances available to reduce or eliminate your bill — is an important part of managing your finances effectively.

📋 Key points
  • What is capital gains tax?
  • The annual exempt amount
  • Reducing your capital gains tax bill

What is capital gains tax?

Capital gains tax is charged on the profit you make when you sell or dispose of an asset that has increased in value. The tax applies to assets including shares and funds held outside an ISA, second homes and investment properties, business assets, and some personal possessions worth more than £6,000.

You do not pay capital gains tax on your main home when you sell it, on assets held inside an ISA or pension, on UK government bonds called gilts, or on personal possessions worth less than £6,000.

The annual exempt amount

Everyone has an annual capital gains tax exempt amount — often called the annual allowance — which allows a certain amount of gains each year completely free of tax. Following recent reductions the allowance is now £3,000 per person per tax year. This is a significant reduction from the £12,300 allowance that existed just a few years ago.

Using the allowance each year is important — it cannot be carried forward. Couples can effectively double the allowance by splitting assets between them before selling.

The rates

Basic rate taxpayers pay 10% on gains from most assets and 18% on residential property gains. Higher and additional rate taxpayers pay 20% on most assets and 24% on residential property.

Reducing your capital gains tax bill

The most effective way to shelter investment gains from capital gains tax is to hold assets inside a Stocks and Shares ISA or pension, where gains are completely tax-free.

For assets held outside an ISA, careful planning around timing — spreading sales across tax years to use annual exemptions — can significantly reduce your bill.

Bottom line

Capital gains tax is increasingly relevant as the annual exempt amount has been reduced sharply. If you hold significant investments outside an ISA, consider moving them into an ISA wrapper over time and take specialist advice if you are selling a property or business.