Hi,
The supplementary page SA108, needs to be downloaded and the capital gains declared on it and submitted with the short tax return.
Self Assessment: Capital gains summary (SA108)
You can deduct acquisition and disposal costs and fees from the disposal value. If the annual exempt allowance has not already been utilised, then £12300 can be deducted. The remainder is taxable at the lower rate of 10%, the upper rate of 20% or a combination of both. Self Assessment will work this out.
Thank you.