Topping up a pension and the effect on CGT on the sale of shares

If a person was to utilise the topping up facility from unused personal pension allowances from this and all the previous three years allowances, effectively creating a position of no taxable income for the current and last 3 years. Would the Capital Gains from the sale of shares in this tax year in a General Investment Account fall within: 1. the personal income tax allowance for this tax year and reduce any CGT due, 2. the current years personal income and be assigned to the pension topping up, increasing what can be added into a personal pension over income just from salary, 3. the current years income and after the £1000 dividend allowance be taxed at the appropriate tax thresholds 0% 8.5% etc or 4. fall outside of the income tax allowance and CGT is due on the whole amount minus this years dividend £1000 allowance or £500 if the sale of shares is over the lower rate tax threshold? I am guessing whatever is done a self assessment would need to be completed to help document the transactions.

Hi S Gilmore,
No, personal allowances, savings allowance or dividend allowance is given against capital gains. you are entitled to £6000 annual exempt amount for 23/24 and this reduces to £3000 on 06/04/24.
Anything above these amounts would be taxed at the appropriate capital gains rate:
Capital Gains Tax: what you pay it on, rates and allowances
Thank you.