Capital Gains Tax UK: A Guide for Individuals and Finance Professionals

Capital Gains Tax (CGT) is the tax on the profit made when you dispose of certain assets that have increased in value. It's an important tax for accountants, business owners and individuals to understand. This guide explains what CGT is, how it works in the UK, the key concepts, and what to be aware of — in clear, plain language. Because CGT rates, allowances and rules change frequently, always check the current position with HMRC or a qualified adviser for your specific circumstances. For broader tax study, see our ACCA TX taxation guide.

What is Capital Gains Tax?

Capital Gains Tax is a tax on the gain you make when you dispose of an asset that has risen in value. Importantly, it's the gain — broadly the increase in value — that's taxed, not the total amount you receive. "Disposing" of an asset usually means selling it, but can also include giving it away, transferring it, or otherwise getting rid of it. CGT typically applies to assets such as investments, second properties, and business assets, among others. Some assets and situations are exempt or treated differently. Understanding what counts as a chargeable disposal, and what the gain is, is the starting point for understanding CGT.

How the gain is calculated

In broad terms, the gain on a disposal is calculated as the proceeds (or value) on disposal, less the original cost and certain allowable costs. Allowable costs can include things like the acquisition cost, costs of buying and selling, and certain costs of improving the asset. Individuals also typically have an annual exempt amount — a tax-free allowance below which gains in a tax year aren't taxed — though the amount of this allowance is set by the government and changes over time. The gain above any available allowance is then potentially subject to CGT. The detailed rules on what costs are allowable, and how gains are computed, can be complex, so checking current guidance is important.

CGT rates and how they apply

The rate of CGT can depend on several factors, including the type of asset disposed of and the individual's level of income, since CGT interacts with income tax. As a result, different rates can apply to different gains and different taxpayers. The specific rates, and the rules around them, are set by the government and change over time — so it's essential to check the current rates rather than relying on a fixed figure. Because of how CGT interacts with income and the type of asset, working out the rate that applies to a particular gain isn't always straightforward, and is an area where care and current information matter.

Reliefs and exemptions

There are various reliefs and exemptions that can reduce or eliminate CGT in certain circumstances. For example, the disposal of an individual's main home often benefits from relief, certain business disposals may qualify for specific reliefs, and transfers between spouses or civil partners are typically treated in a particular way. The availability and details of these reliefs are set out in the rules and change over time, and they often come with specific conditions. Because reliefs can significantly affect the CGT position, identifying which might apply — and checking the current conditions — is an important part of getting CGT right. Specialist advice is often valuable here.

Why understanding CGT matters

For individuals, business owners and their advisers, understanding CGT matters because it affects the after-tax outcome of selling assets, and because getting it wrong can lead to unexpected tax bills or missed opportunities to use reliefs and allowances. Good planning — such as timing disposals, using available allowances, and identifying reliefs — can make a real difference, though it must always be done within the rules. Because CGT is detailed and changes regularly, this guide is a general overview only. Always check the current rates, allowances and rules with HMRC, and seek qualified advice for specific situations, rather than relying on general information alone.

Frequently asked questions

What is Capital Gains Tax?

A tax on the gain made when you dispose of an asset that has risen in value — it's the gain, not the total proceeds, that's taxed.

How is the gain calculated?

Broadly as the disposal proceeds less the original cost and certain allowable costs, with individuals typically having an annual tax-free allowance — the amount of which changes over time.

What rate of CGT applies?

It can depend on the type of asset and the individual's income, as CGT interacts with income tax. Rates are set by the government and change, so always check the current rates.

Are there reliefs from CGT?

Yes — various reliefs and exemptions can reduce or eliminate CGT in certain circumstances, such as for a main home or certain business disposals, subject to current conditions.

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