Declaration of sale of inherited shares

After my Mother's death some of her shares were appropriated to myself & my siblings as bare trustees (we were joint executors) & subsequently sold on our behalf as individuals. Our solicitor informed us that we would need to declare the sale on our tax returns but I'm confused as to whether it counts as income or if it is in relation to CGT. My self-assessment UTR did not come in time for me to deal with it in the relevant year so now I'm unsure whether I need to make an unpaid tax disclosure of income (I already started this process online) or if it's something else. Thank you.

Hi,
You will need to amend the tax return you submitted and declare your capital gains in the capital gains section.
Thank you.