Tax2 min read · Updated 21 October 2026
Six legal ways to cut your capital gains tax bill
Six legitimate ways to reduce UK capital gains tax: use ISAs and pensions, spread gains over years, share with a spouse, count your costs, and use losses.
Use the allowance each year
The £3,000 allowance is use it or lose it. If you hold shares with a gain, selling part each year and buying back inside an ISA is a common approach. Remember the 30-day rule: buying back the same shares within 30 days in a normal account can undo the sale for tax.
Wrap investments
Gains in an ISA or pension are free of this tax. Fill the ISA first with new money, and move investments into it over time.
Share with a spouse
Transfers between spouses or civil partners are tax-free. If your partner pays tax at 18% and you pay 24%, moving part of the asset first can save 6% of the gain, and uses a second allowance.
Count every cost
Fees, stamp duty and improvement costs reduce the gain. Keep records from the day you buy.
Common questions
Can I carry the allowance forward?
No. The £3,000 is lost if you do not use it.
What is the 30-day rule?
Buying the same shares back within 30 days of selling them changes which cost is used. Get advice for larger sales.
Do I need to report a gain?
If gains are above the allowance, you normally report them to HMRC. Check the current rules.