Chris here. Thanks very much for your rapid and clear response. I really appreciate it. In terms of evidence, presumably that would be their self-assessments, right? Anything else? That's a good point. I mean that would be more than enough evidence I should think. Is there anything in particular you would expect to see in their invoice to me? OR can it simply be "[services] completed on behalf of [limited company] by [name of colleague] for October 2014
In your experience would the HMRC ever want to know what work it was in particular?