Readers’ forum: How can I prove disposal without written document?

HMRC has raised an enquiry into my client’s capital gains tax position for 2022-23.

One of the disposals was of a minority holding in a company where the majority ‘did a deal’ and the minority were forced to sell under a ‘drag-along’ notice.

My client received a voluminous sale and purchase agreement (SPA) but none of the minority shareholders signed it because they thought it might prejudice their rights in any legal action that they might take (but in the event never did). The officer carrying out the enquiry has asked several times for a signed and dated SPA citing various references to the HMRC manuals in support of her right to see such a thing.

I have told her that it does not exist and why and provided the unsigned copy and an email from the company which says ‘the sale transaction...