Capital Gains - reduce with pension contribution?

MEM62

Here's one for you knowledgeable folk.  

When my OH and I bought a house together some six years ago I kept my flat.  I have now decided to sell, which is going to leave me with a CGT liability.  The ballpark figures are as follows;

Flat purchased in December 1987 for £50K
Will sell this year for circa £285K (assume May completion for calculation purposes only)
It was my residence from December 1987 to March 2016 and has been rented since. 
Costs for selling around £6K
Total personal income including rent £70K pa.
Current pension contributions NET £15,900 including employer contribution.    

HMRC's calculator gives a Capital Gains figure of just under £10K.  Can I reduce this buy an additional payment into my pension?  Regardless of the the answer I intend to feed as much of this money into me pension as I can over the next few years anyway.  I calculate that my grossed up contributions are currently £18,900 pa so can contribute an extra £16,000 pa for the next few years.

Your opinions would be appreciated.    

Jeremy535897

Sale proceeds £285,000 less cost £50,000 less fees say £6,000 leaves a gain of £229,000.

December 1987 to March 2016 is 340 months plus last 9 months ownership gives an exempt period of 349 months. Total ownership to May 2021 is 411 months. Chargeable gain is £229,000 x 62/411 = £34,545 less annual exemption of £12,300 = £22,245, which at 28% is £6,228.60.

You cannot set pension contributions against capital gains. If you make pension contributions you will increase your basic rate band which could reduce the tax rate to 18% on all or part of the gain, depending on the figures. See:
https://www.gov.uk/capital-gains-tax/rates

You have to declare and pay the capital gains tax within 60 days of completion:
https://www.gov.uk/capital-gains-tax/report-and-pay-capital-gains-tax

Giving a share to your spouse/civil partner (assuming one of these applies) before marketing the property may reduce the tax payable if they have their annual capital gains tax exemption available and/or are a basic rate taxpayer. They would become entitled to part of the rent prior to sale. This needs proper advice before contemplating, and may be more complicated if there is a mortgage, but the longer between the transfer and the sale, the better.

MEM62

Thanks for that.  I got my head around the fact that I cannot offset but was not clear on the mechanism for the additional pension contributions increasing my basic rate band.  I should also have considered the fact that my earnings for that tax year (2022/23), before pension contributions, will actually be £60K and not £70K as the income from the flat will stop.   

Interestingly, HMRC's online calculator gives me a liability figure of £9,800 although I am able to follow your calculations.   

Jeremy535897

When I went through the calculator, I got the same figure as above, £6,228.60.