(1) Detailed assessment proceedings are commenced by the receiving party serving on the paying party —
(a) a notice of commencement in Form 24A; and
(b) a copy or copies of the bill of costs.
(2) The receiving party must also serve a copy of the notice of commencement and the bill of costs on any other person specified in the relevant Practice Direction.
(3) A person on whom a copy of the notice of commencement is served under paragraph (2) is deemed to be a party to the detailed assessment proceedings (in addition to the paying party and the receiving party).