Selling a buy to let property

Hi , My son is selling his buy to let property. When the sale goes through he will be doing his capital gains return He will have a redemption fee to pay when he pays the mortgage off on completion as he is still in a mortgage deal . Can he put that figure onto his year end self assessment tax return ? if so what section will it come under ? his expense section or another section

Hi,

A mortgage is a means of acquiring an asset and is not relevant in calculating capital gains liability.  There is no tax relief available for mortgages.

Thank you.