UK Capital Gains Tax: A Beginner's and Advanced Guide

Capital Gains Tax (CGT) is a tax on the profit you make when you sell or dispose of an asset that has increased in value. This guide breaks down how CGT works in the UK, from the basics for beginners to advanced strategies for experienced investors, complete with examples and tax-saving tips.

What is Capital Gains Tax?

CGT is not a tax on the total amount of money you receive from a sale. It's a tax on the gain—the difference between what you paid for an asset and what you sold it for. You only pay CGT on assets that have gone up in value.

Common assets subject to CGT include:

What is exempt from CGT?

The Capital Gains Tax Annual Exempt Amount

Every UK taxpayer gets an annual tax-free allowance for capital gains. For the 2025/26 tax year, this allowance is £3,000. You only pay CGT on gains that exceed this amount. If your total gains for the tax year are less than or equal to this figure, you have no CGT to pay.

It's a "use it or lose it" allowance. You can't carry any unused portion forward into the next tax year.

How to Calculate Your Capital Gains Tax Liability

Calculating your CGT liability involves a few key steps. It's a bit like a jigsaw puzzle where each piece is a part of your financial picture.

  1. Work out your gain: Subtract the original purchase cost and any associated costs (e.g., stamp duty, solicitor fees, or estate agent fees) from the sale price.
  2. Deduct the Annual Exempt Amount: Subtract your £3,000 allowance from the total gain.
  3. Apply the correct tax rate: The rate of CGT you pay depends on your total taxable income (including your salary, rental income, etc.) and the type of asset you're selling.

Capital Gains Tax Rates (2025/26 Tax Year)

Your CGT liability is added on top of your taxable income. This means your tax rate depends on which tax band your gains fall into.

Capital Gains Tax Example Calculation

Let's walk through an example to make this clearer.

Imagine you're a basic rate taxpayer with a salary of £30,000. You sell some shares for a gain of £10,000. The original purchase price was £20,000, and you sold them for £30,000.

  1. Work out your gain: £30,000 (sale price) - £20,000 (purchase cost) = £10,000 gain.
  2. Deduct the Annual Exempt Amount: £10,000 - £3,000 = £7,000 taxable gain.
  3. Calculate the tax due: Your £7,000 taxable gain sits on top of your £30,000 salary. Since you are a basic rate taxpayer, the gain is taxed at the basic rate for shares.

Tax due: £7,000 x 10% = £700 CGT payable.

Ready to see how your own tax liability looks?

Our user-friendly capital gains tax calculator takes into account your other income sources to provide a clear and accurate estimate of what you'll owe.

Advanced Strategies for Managing Capital Gains Tax

For more experienced investors, simply using the annual allowance isn't enough. Here are some advanced strategies to consider:

1. Bed and Breakfasting (now illegal) and Bed and Sponsing

"Bed and Breakfasting" was a strategy where you sold an asset, realized the gain up to your allowance, and then immediately bought it back. This is now illegal. The current rule is you must wait 30 days before repurchasing the same asset.

Instead, many investors use a "Bed and Sponsing" strategy. This involves selling an asset and then immediately buying it back into your spouse or civil partner's name. This allows you to realize the gain while the asset remains in the family, and your partner gets their own CGT allowance when they sell in the future.

2. Capital Losses

If you sell an asset for less than you paid for it, you have a capital loss. You can use these losses to reduce your total gains.

3. Gifting Assets

Gifting an asset to your spouse or civil partner is completely CGT-free. They are considered to have acquired the asset at the same price you did. This is a powerful tool for using their CGT allowance, as they can sell the asset later, and any gain will be offset by their own annual allowance.

4. Using Tax-Efficient Accounts

The easiest and most effective way to avoid CGT is to hold your investments in tax-efficient wrappers.

Reporting Capital Gains to HMRC

If you have a taxable gain, you must report it to HMRC via a Self Assessment tax return.

Don't get caught out by HMRC deadlines. Our calculator helps you understand your liability so you can plan ahead.