CTM15940 - Distributions: non-qualifying distributions: nominees
You should check the other guidance available on GOV.UK from HMRC as Brexit updates to those pages are being prioritised before manuals.
Where the recipient of a non-qualifying distribution is a nominee, CTA10/S1102 gives HMRC power to ascertain the beneficial owner of the shares. This information will be sought first from the company (or its agent) making the distribution. If the company is unable to supply the information it will be sought from the person in whose name the shares etc are registered.