How to carry forward a loss in selling of shares

Hi HMRC Admin, I've made a loss in selling of shares in the tax year 2023-24, please advise which box(es) I must fill in my tax return so that I could carry forward the loss to next year? And will there be a deadline if I do not claim the loss next year? Thanks.

Hi
You have 4 years from the end of the tax year that the loss arises, to declare the losses.  If you are completing SA108, you would complete the section named "Losses and adjustments", page CG3.  In the online tax return, you will need to tick 'yes' to declare capital gain, when tailoring your tax return.  You would then declare what you want to do in the section "Losses and adjustments".