“(1) This section applies where and to the extent that any 2 or more persons jointly carry out an activity listed in Schedule 3 or 4, including (but not limited to) in partnership, under an unincorporated joint venture, as trustees of a trust, through joint ownership of land, or under an unincorporated association.
“(3) Each person who is or has ceased to be a member of an unincorporated body is, in respect of the period during which the person is or was a member of the unincorporated body,—
“(6) A notice that is addressed to an unincorporated body and given in accordance with this Act to the person nominated by the unincorporated body in its notice or application under subsection (2)(d)(iii) or (if relevant) under section 157A(2)(a) is to be treated as notice given to that unincorporated body and all members of the unincorporated body.
“(7) In this section and section 157A,—
“member means a partner, joint venturer, trustee, joint owner of land, or other member of an unincorporated body (as applicable in the circumstances)
“unincorporated body includes (but is not limited to) a partnership, an unincorporated joint venture, a trust, joint owners of land, or an unincorporated association (as applicable in the circumstances).