Capital Gains Tax on a £10,000 Gain 2026/27
After the £3,000 annual exempt amount, a basic-rate taxpayer (£35,000 other income) owes £1,260 CGT on a £10,000 gain. A higher-rate taxpayer (£55,000 other income) owes £1,680.
On a £10,000 gain the allowance still takes a large bite. £7,000 is taxable, so a basic-rate seller pays £1,260 and a higher-rate seller £1,680: 12.6% and 16.8% of the whole gain. This is a typical result of selling part of a share portfolio held outside an ISA, and it is the first size on this list where it starts to matter exactly where your income sits.
Which rate does a £10,000 gain pay at different incomes?
| Other income | Band left | At 18% | At 24% | CGT |
|---|---|---|---|---|
| £20,000 | £30,270 | £7,000 | £0 | £1,260 |
| £35,000 | £15,270 | £7,000 | £0 | £1,260 |
| £45,000 | £5,270 | £5,270 | £1,730 | £1,363.80 |
| £55,000 | £0 | £0 | £7,000 | £1,680 |
With £7,000 taxable, the gain stays wholly at 18% until your income before tax passes £43,270. Someone on £45,000 is above that line: they have £5,270 of basic-rate band left, so the other £1,730 is taxed at 24% and the bill is £1,363.80. Crossing the line costs at most £420, but people close to a pay rise or a bonus often don't realise their gain is measured against it.1
Can you pay less on a £10,000 gain?
| Option | CGT | Saving |
|---|---|---|
| Sell it all in 2026/27 | £1,680 | - |
| Half before 6 April 2027, half after | £960 | £720 |
| Half given first to a spouse with no income | £840 | £840 |
| Half given first to a spouse earning £35,000 | £840 | £840 |
| £10,000 gross pension contribution | £1,363.80 | £316.20 |
| £20,000 gross pension contribution | £1,260 | £420 |
Spreading the sale over two tax years
Two tax years turn one taxable gain of £7,000 into two of £2,000, because each year brings its own £3,000 allowance and its own band. The engine puts the saving at £540 for a seller on £35,000 and £720 on £55,000: a second allowance taxed at 18% or 24%. The 2027/28 allowance is confirmed at £3,000.2
Giving half to a spouse or civil partner
Transferring half to a spouse before the sale saves £840 if they have no other income and £840 if they earn £35,000. In both cases their £5,000 share is taxed at 18% after their own allowance, while your half stays at 24%. If your spouse is a higher-rate taxpayer too, the saving drops to £720, the second allowance alone. It has to be an outright gift, and it only works while you live together.3
Pensions, ISAs and reliefs
For a seller on £55,000, a £10,000 gross pension contribution saves £316.20 of CGT, not £600. The first £4,730 of it only brings income back down to £50,270 before any extra band reaches the gain.4 A £20,000 contribution saves £420, the full 6 points on £7,000. The contribution earns income tax relief of its own,7 so the CGT saving is a bonus rather than a reason to pay in.
Reporting and paying the tax
A taxable gain of £7,000 has to be reported: on your 2026/27 tax return, filed and paid by 31 January 2028, or through the real-time service by 31 December 2027 if you are not in Self Assessment.5 The £50,000 test in HMRC's notes is about the value of what you sold, not the gain.6 A £10,000 profit on a holding that cost £45,000 means £55,000 of proceeds, which needs the capital gains pages even in a year when losses wipe out the tax.
Your own figures: use the full calculator → for your sale price, costs, losses and income.
CGT on other gain amounts
Frequently asked questions
How much of a £10,000 gain can a married couple make tax-free?
£6,000 between you: each spouse or civil partner has a £3,000 annual exempt amount for 2026/27. If the shares are in one name, giving half to your spouse before the sale lets both allowances apply.
Is CGT on a £10,000 gain different for shares and property?
Not the rate: in 2026/27 residential property and other assets are both taxed at 18% and 24%. The deadline differs. A UK home that is not your main residence needs a 60-day return and payment when there is tax to pay.
What is the effective tax rate on a £10,000 gain?
12.6% for a basic-rate seller on £35,000 and 16.8% for a higher-rate seller on £55,000, measured against the whole £10,000. The headline 18% and 24% only apply to the £7,000 left after the allowance.
Figures from our calculator engine, 7 November 2026. Guidance only, not advice.
Sources & references
The rates, allowances and rules in this guide are drawn from the official HMRC and GOV.UK sources below, checked for the 2026/27 tax year. Each link opens the relevant government page in a new tab.
- Capital Gains Tax: rates www.gov.uk/capital-gains-tax/rates
- Budget 2026 OOTLAR, Annex A: rates and allowances (2026/27 and 2027/28) www.gov.uk/government/publications/budget-2026-overview-of-tax-legislation-and-rates-ootlar/annex-a-rates-and-allowances
- Capital Gains Tax: gifts to your spouse or charity www.gov.uk/capital-gains-tax/gifts
- Finance Act 2004, section 192: relief at source (basic rate limit increased by the contribution) www.legislation.gov.uk/ukpga/2004/12/section/192
- Report and pay CGT: if you have other capital gains to report www.gov.uk/report-and-pay-your-capital-gains-tax/if-you-have-other-capital-gains-to-report
- Self Assessment: Capital Gains summary (SA108) and notes www.gov.uk/government/publications/self-assessment-capital-gains-summary-sa108
- Tax on your private pension contributions: tax relief www.gov.uk/tax-on-your-private-pension/pension-tax-relief