Most people know that pension contributions reduce income tax. Fewer realise they can also reduce the CGT on a property sale. The mechanism is indirect but genuinely effective — and with CGT rates at 18% versus 24% for residential property, the saving can be meaningful.
How CGT rates work in 2026/27
Capital gains on UK residential property are taxed at either 18% or 24%, depending on whether the gain (when added to your taxable income) falls within or above the basic rate band.
For 2026/27, the basic rate band runs from £0 to £50,270. If your taxable income for the year is £40,000, you have £10,270 of basic rate band remaining. The first £10,270 of your net property gain falls within that band and is taxed at 18%. The remainder is taxed at 24%.
If your total taxable income already exceeds £50,270, the entire gain is taxed at 24%.
How pension contributions extend the basic rate band
When you make a pension contribution, your basic rate band extends by the gross contribution amount. HMRC effectively treats the pension contribution as pushing the ceiling of the basic rate band upwards.
For example:
- Taxable income: £55,000 (entirely in higher rate territory)
- Gross pension contribution: £10,000
- Extended basic rate band: £50,270 + £10,000 = £60,270
- Net property gain: £40,000
Without the pension contribution, all £40,000 is taxed at 24% = £9,600.
With a £10,000 gross pension contribution, £5,270 of the gain falls within the extended basic rate band at 18%, and £34,730 at 24%. Total CGT = £949 + £8,335 = £9,284.
Saving: £316 on a £10,000 contribution. That is modest in isolation, but with larger contributions (the annual allowance for most people is £60,000 gross), the saving scales significantly.
The timing: contribution must be in the same tax year
The pension contribution must be made in the same tax year as the property disposal. The tax year runs 6 April to 5 April. If your property completes in March 2026, a pension contribution made before 5 April 2026 is in the same tax year. A contribution made on 7 April 2026 is in the following tax year and has no effect on the 2025/26 CGT calculation.
You have until 5 April to make the contribution. If the property has already completed (triggering the 60-day return), you can still make the pension contribution before the tax year ends and it will reduce the CGT. However, if the CGT was already paid via the 60-day return, the benefit flows through Self Assessment as a reduction in your final tax bill or a repayment.
The 60-day return complication
The 60-day CGT return requires you to estimate your income and other tax facts for the full tax year. If you are planning a pension contribution to reduce your CGT rate but have not yet made it at the time of filing the 60-day return, you have two options:
- Make the pension contribution before completing the 60-day return, then include the reduced rate calculation in the return.
- File the 60-day return at the higher rate, make the pension contribution before 5 April, and claim the difference back through Self Assessment.
Option 1 is cleaner. If you are working with an accountant on your 60-day return, tell them about any planned pension contributions at the outset so the return reflects the correct rate.
Carry-forward of unused pension allowance
If you have not used your full pension annual allowance in the three previous tax years, you may be able to carry that unused allowance forward and make a larger contribution in the current year. A £40,000 or £60,000 contribution in the tax year of a large property gain can shift the effective rate on a significant portion of the gain from 24% to 18%.
Does this work for all pension types?
It works for personal pensions (SIPPs and personal pension plans) where you make contributions yourself. Employer contributions do not affect your basic rate band extension in the same way for CGT purposes. The contribution must be to a registered UK pension scheme.
The practical upshot
If you are selling a property with a substantial gain and you have pension allowance available, making a contribution before 5 April can reduce your CGT bill at 18% versus 24% on the affected slice of the gain. On a £100,000 gain with £50,000 in the higher rate band, a £50,000 gross pension contribution could save £3,000 in CGT (6% differential on £50,000).
To understand the full interaction between your income, the property gain, and a pension contribution, talk to a Chartered Accountant/Chartered Tax Advisor before the tax year ends. The numbers depend on your specific income position and the gain calculation.