CGT Tax due has changed on Self Assessment

Hi, I sold a property in July 2022 so paid the tax due immediately. Now, using exactly the same figures on this years SA the figures have gone up, surprisingly. I made a gain of £30,443 and the tax I was told to pay was £5497.04. When I put this figure into the boxes in SA it shows the calculation of a £30,443 gain as £22,879 x 18% = 4118.22 and £7564 x 28% = 2117.92?? Can you please explain how the tax due has now changed as the figures are exactly the same as when I paid them? Thank you for your assistance.

Hi, I haven't heard anything back from my query yet, can you please assist me with this? Thank you

Hi,

Income tax is calculated first, before Capital Gains Tax is calculated. Any of the unused basic rate band can then be applied against the lower rate of Capital Gains Tax.

When you declared the income using the online service, your Income Tax liabilites, such as employment, self employment, partnership and property income, would be estimated. Now you are submitting your tax return, those figures are accurate.  

For more Capital Gains Tax to be payable, would mean that the income declared on the tax return is higher than on the online capital gains service, so less basic rate is available to apply to the lower capital gain, increasing the amount taxed at the upper capital gain rate of 28%.

Thank you.