Don’t forget that by April 5th the tax year ends, and your Capital Gains Allowance resets.
This current year the allowance is £12,300.
So if you were planning on cashing in more than that, try and manage it so that you maximise both this year and next years allowance. Otherwise you will need to pay between 10 and 20 % on any profit made above the allowance.
More info: https://www.gov.uk/capital-gains-tax