HI
We would suggest that you first seeks guidance from our Corporation Tax team, or,ideally, seek professional advice from an accountant. There are just a few too many unknowns here for us to provide definitive guidance, but the Gov.UK document below on selling or closing a company might prove useful reading. The document in question provides advice on the selling of assets used by a limited company and explains that in certain circumstances Corporation Tax is payable by the company rather than CGT by the shareholder. It also covers circumstances where shareholders may be personally liable. Once more facts are established it might be possible to advise you further on reporting responsibilities.
Corporation Tax: selling or closing your company