Capital Gains Tax on a £100,000 Gain 2026/27
After the £3,000 annual exempt amount, a basic-rate taxpayer (£35,000 other income) owes £22,364 CGT on a £100,000 gain. A higher-rate taxpayer (£55,000 other income) owes £23,280.
On a £100,000 gain the household planning reaches its ceiling. £97,000 is taxable and the bill runs from £21,463.80 to £23,280 depending on income. Giving half to a spouse with no income saves £2,982, the largest saving a spouse transfer can produce; no bigger gain on this site saves more.
Which rate does a £100,000 gain pay at different incomes?
| Other income | Band left | At 18% | At 24% | CGT |
|---|---|---|---|---|
| £20,000 | £30,270 | £30,270 | £66,730 | £21,463.80 |
| £35,000 | £15,270 | £15,270 | £81,730 | £22,363.80 |
| £45,000 | £5,270 | £5,270 | £91,730 | £22,963.80 |
| £55,000 | £0 | £0 | £97,000 | £23,280 |
Each person's basic-rate band can take at most £37,700 of gain at 18%. At £100,000 the gain dwarfs it: even a seller on £20,000 has £66,730 at 24%. What drives the bill now is the size of the taxable gain, so anything that reduces the gain itself is worth 24p in the pound to a higher-rate seller.1
Every seller in the table pays 24% at the margin, so a further £10,000 of gain adds £2,400. That is the same whether the extra comes from a higher sale price or from costs you cannot evidence, which makes the purchase records worth finding before you file.
Can you pay less on a £100,000 gain?
| Option | CGT | Saving |
|---|---|---|
| Sell it all in 2026/27 | £23,280 | - |
| Half before 6 April 2027, half after | £22,560 | £720 |
| Half given first to a spouse with no income | £20,298 | £2,982 |
| Half given first to a spouse earning £35,000 | £21,643.80 | £1,636.20 |
| £10,000 gross pension contribution | £22,963.80 | £316.20 |
| £20,000 gross pension contribution | £22,363.80 | £916.20 |
Spreading the sale over two tax years
Splitting a share sale over two tax years saves £1,636.20 or £720, both now fixed amounts. Against a £23,280 bill that is a small slice, though still worth having if you were going to sell around April anyway.
Giving half to a spouse or civil partner
The spouse saving of £2,982 is two things added together: a second £3,000 allowance at 24% (£720) and a full second basic-rate band at the 6-point difference (£2,262).21 Any gain of £81,400 or more gets this same maximum.
Pensions, ISAs and reliefs
Losses are the lever that scales. A same-year loss reduces the gain pound for pound, and a loss carried forward reduces it down to the allowance.6 At 24%, each £1,000 of loss used saves £240. If you hold investments standing at a loss, selling them in the same tax year is worth checking before 5 April 2027.
Reporting and paying the tax
Reporting is certain at this size. Shares: on your tax return by 31 January 2028, or the real-time service by 31 December 2027 with payment by 31 January 2028.3 Property: 60 days from completion.4 The capital gains pages are needed because proceeds exceed £50,000.5
Your own figures: use the full calculator → for your sale price, costs, losses and income.
CGT on other gain amounts
Frequently asked questions
What is the most a spouse transfer can save?
£2,982 in 2026/27: one extra allowance at 24% plus a full basic-rate band at the 6-point gap. Any gain of £81,400 or more saves the same amount this way.
How much tax on £100,000 of capital gains at 24%?
£23,280 for a seller with £55,000 of income: the £97,000 left after the allowance, all at 24%.
Can I pay the CGT on £100,000 before the deadline?
Yes. For shares the deadline is 31 January after the tax year, and HMRC charges late payment interest only from that date. Paying earlier does not reduce the tax itself.
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
- Capital Gains Tax: gifts to your spouse or charity www.gov.uk/capital-gains-tax/gifts
- 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
- Self Assessment: Capital Gains summary (SA108) and notes www.gov.uk/government/publications/self-assessment-capital-gains-summary-sa108
- Capital Gains Tax: losses www.gov.uk/capital-gains-tax/losses