Capital Gains Tax on a £15,000 Gain 2026/27
After the £3,000 annual exempt amount, a basic-rate taxpayer (£35,000 other income) owes £2,160 CGT on a £15,000 gain. A higher-rate taxpayer (£55,000 other income) owes £2,880.
A £15,000 gain leaves £12,000 taxable after the allowance, and that is the figure to watch. It is just under the £15,270 of basic-rate band someone on £35,000 has spare, so a typical basic-rate taxpayer pays 18% on all of it, £2,160. A higher-rate seller pays £2,880.
Which rate does a £15,000 gain pay at different incomes?
| Other income | Band left | At 18% | At 24% | CGT |
|---|---|---|---|---|
| £20,000 | £30,270 | £12,000 | £0 | £2,160 |
| £35,000 | £15,270 | £12,000 | £0 | £2,160 |
| £45,000 | £5,270 | £5,270 | £6,730 | £2,563.80 |
| £55,000 | £0 | £0 | £12,000 | £2,880 |
The line for keeping everything at 18% is an income of £38,270. Above it the gain spills: at £45,000, £6,730 of the £12,000 is charged at 24% and the bill reaches £2,563.80, close to the higher-rate figure. That is the pattern for gains of this size. A few thousand pounds more salary barely changes your income tax, but it can switch most of the gain to the higher CGT rate.1
Can you pay less on a £15,000 gain?
| Option | CGT | Saving |
|---|---|---|
| Sell it all in 2026/27 | £2,880 | - |
| Half before 6 April 2027, half after | £2,160 | £720 |
| Half given first to a spouse with no income | £1,890 | £990 |
| Half given first to a spouse earning £35,000 | £1,890 | £990 |
| £10,000 gross pension contribution | £2,563.80 | £316.20 |
| £20,000 gross pension contribution | £2,160 | £720 |
Spreading the sale over two tax years
Splitting the sale across 5 April 2027 saves £540 for a basic-rate seller and £720 for a higher-rate one. For the basic-rate seller the gain was already all at 18%, so the saving is only the second allowance; splitting does not change the rate. Rates, allowance and bands are confirmed unchanged for 2027/28,2 so the second half is taxed the same way.
Giving half to a spouse or civil partner
Spouse planning beats splitting here. With half moved to a spouse who has no income, the gain is taxed as two £7,500 gains with two allowances, and the spouse's share is charged at 18% instead of 24%. The household saves £990, against £720 if your spouse is also a higher-rate taxpayer.3
Pensions, ISAs and reliefs
A higher-rate seller would need a £16,730 gross pension contribution to bring the whole £12,000 back to 18%, which saves £720; a £10,000 contribution saves £316.20.4 An ISA cannot help with this gain, because a gain already made is taxed when you sell. The proceeds can go into an ISA, up to £20,000 a year, so the next rise is sheltered.7
Reporting and paying the tax
With tax due on £12,000, you report it. If you sold shares and are not in Self Assessment, the real-time service deadline for a 2026/27 gain is 31 December 2027, with payment by 31 January 2028.5 A tax return filer puts it on the capital gains pages. If the asset was UK residential property other than your home, report and pay within 60 days of completion.6
Your own figures: use the full calculator → for your sale price, costs, losses and income.
CGT on other gain amounts
Frequently asked questions
Can I keep a £15,000 gain entirely at 18%?
Yes, if your income before tax is no more than £38,270, because the £12,000 taxable gain then fits in your basic-rate band. Above that line, paying more into a workplace pension by salary sacrifice or net pay lowers your taxable pay pound for pound. Finance Act 2004 section 192(4) extends the basic rate limit for a personal pension contribution only where some of your income would otherwise be taxed at the higher rate.
Is it better to take a £15,000 gain this tax year or next?
If you have not used this year's £3,000 allowance, selling part now and part after 5 April 2027 saves £540 to £720, depending on your rate. If you have, selling all of it after 5 April 2027 uses next year's allowance instead.
What if I made a loss on another holding the same year?
Same-year losses are deducted in full before the allowance. The tax is then worked out on the smaller gain, exactly as on our pages for smaller gains, so a £5,000 loss leaves you with the bill on the £10,000 page.
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
- Report and pay CGT: if you sold a UK property on or after 6 April 2020 www.gov.uk/report-and-pay-your-capital-gains-tax/if-you-sold-a-property-in-the-uk-on-or-after-6-april-2020
- Individual Savings Accounts (ISAs) www.gov.uk/individual-savings-accounts