Section 257DH | The no partnerships requirement
From legislation.gov.uk
(1)Neither the issuing company nor any qualifying 90% subsidiary of that company may, at any time during period A, be a member of a partnership.
(2)“Partnership” includes—
(a)a limited liability partnership, and
(b)an entity established under the law of a territory outside the United Kingdom of a similar character to a partnership,
and “member”, in relation to a partnership, is to be read accordingly.