Selling investments can create a tax liability, but it isn’t always obvious when Capital Gains Tax (CGT) applies. People often get confused about paying CGT when they sell an investment. Some investors assume tax is due on the full amount they withdraw, and others believe all investments are treated the same way. In this blog, we explain how CGT applies to your investment portfolio.
Which investments generate a taxable gain?
For people with larger portfolios held across ISAs, pensions and general investment accounts, understanding which investments could create a taxable gain becomes increasingly important. Therefore, we’ve answered some common questions below:
How is an investment gain calculated?
When you sell an investment, it can create a CGT liability, which is usually charged on the profit and not the amount withdrawn. The tax treatment will depend on the type of investment, holding account, and your total gains and losses for the tax year.
An investment gain is calculated using the following:
Capital gain = sale proceeds – purchase cost – allowable costs
Your ‘allowable costs’ include trading fees, transaction taxes and certain professional charges. You would then add together your gains from all taxable investments and deduct your allowable losses.
For shares that are bought at different times, HMRC has share-matching rules. This may require a more complex calculation than simply comparing the latest sale price with an original purchase price.
What counts as a disposal for CGT purposes?
A ‘disposal’ usually occurs when an investment is sold, exchanged for another asset, given away or transferred to someone else. It can also apply if you were to receive compensation, such as an insurance payout, for an asset that has been lost or destroyed.
A disposal can involve all or only part of an investment. HMRC has share-matching rules for shares that can affect which purchase cost is used. For example, if a purchase was made on the same day or within the following 30 days.
What is the annual CGT exemption?
For individuals, the annual exempt amount for CGT is £3,000 (tax year 2026/27). Any gains up to this amount are usually CGT-free, but unused allowances cannot be carried forward. This allowance is separate from the annual ISA allowance and applies to your combined taxable gains for the tax year (not separately for each investment account).
What are the current CGT rates for investments?
From 6 April 2026, taxable gains on most investments are charged at 18% for the basic-rate band and 24% for higher or additional rate bands. The rate will depend on how much of your taxable gain falls within your available basic rate income tax band. There are also special rules and rates, such as Business Asset Disposal Relief and Investors Relief. Please speak to our financial planners for advice about available reliefs for CGT.
Can investment losses potentially offset gains?
Yes, allowable losses from investments can generally be deducted from gains in the same tax year. If the losses exceed your current-year gains, then the unused balance can usually be carried forward to reduce gains in later years. Losses would normally be claimed through your Self Assessment tax return or HMRC’s alternative CGT process. You can usually make a claim within four years after the tax year in which the CGT loss occurred.
Can you transfer CGT allowances between spouses and civil partners?
As transfers between spouses and civil partners are usually made on a no gain, no loss basis, this doesn’t normally create a CGT bill. The receiving spouse or partner would take over the original investment acquisition history in preparation for a disposal later on.
As a result, couples can make use of two annual CGT exemptions or different income tax bands. But the transfer must be genuine, as wider investment ownership and estate planning consequences would need to be considered.
Why are investments held within ISAs and pensions treated differently?
Normally, CGT doesn’t apply to investments held within a Stocks and Shares ISA. As the annual CGT exemption doesn’t apply to growth and disposals within the ISA, gains are not usually included on a Self Assessment tax return.
Pension investments are not usually subject to CGT while they remain within a pension.
In some instances, tax may be liable when money is withdrawn, depending on the pension rules, available tax-free amount, and your Income Tax position.
In comparison, general investment accounts, such as shares, funds and unit trusts, might create taxable gains when disposed of. However, certain UK government gilts and other qualifying investments might have separate exemptions.
How and when is CGT reported and paid?
Reporting taxable investment gains is usually done through your Self Assessment tax return for the year in which the disposal occurred. If you’re eligible, you might also be able to use HMRC’s real-time CGT service by the 31st of December in the tax year after the disposal.
It’s worth noting that even when there isn’t any CGT payable, you may still need to report gains. It’s important to keep records of investment purchases, sale dates, sale prices, trading fees and other relevant costs, as well as calculations of gains and losses.
Why selling investments for tax reasons may be unhelpful
Selling investments purely for tax reasons may not always be the right solution to support a wider investment strategy. Tax considerations should only form part of an investment decision, rather than being the reason for making one.
Selling an investment just to use an annual exemption could have other consequences:
- You might move your portfolio away from the intended asset allocation.
- You could trigger extra fees such as trading costs and spreads.
- Selling might create market-timing risk.
- You could miss out on future growth or income.
- Selling an investment may impact your long-term investment strategy.
A more balanced approach is to review whether the investment still fits your portfolio and then assess the tax consequences.
Best Investment Advice Firm – 2026 Money Marketing Awards
Holding stocks, shares or investment portfolios can be a more tax-efficient strategy than holding cash, but different assets can create different taxable gains. Before selling an investment, consider whether there’s a CGT impact.
Balance: Wealth Planning is very proud to have won ‘Best Investment Advice Firm’ at the 2026 Money Marketing Awards. Our qualified financial planners provide tax-efficient advice for investments, and we have our own investment portfolios with 10 risk levels. We can also advise you on spousal transfers, Business Asset Disposal Relief and Investors’ Relief.
If you’re concerned about the impact of Capital Gains Tax on your investments, get in touch to speak to our financial planning team.
Sources:
https://www.gov.uk/capital-gains-tax
https://www.gov.uk/guidance/capital-gains-tax-rates-and-allowances
https://www.gov.uk/hmrc-internal-manuals/capital-gains-manual/cg12700
https://www.gov.uk/capital-gains-tax/what-you-pay-it-on
https://www.gov.uk/capital-gains-tax/work-out-need-to-pay
