(1) A claimant may add a new defendant to proceedings without permission at any time before the date fixed by the court for the first case management conference or at any time on an application to the court.
(2) The claimant does so by filing at the court office an amended claim form and statement of claim, and Parts 5 (service of claim within jurisdiction), 7 (service of court process out of jurisdiction), 9 (acknowledgment of service and notice of intention to defend), 10 (defence and counterclaim) and 12 (default judgments) apply to an amended claim form as they do to a claim form.
• Part 18 deals with the adding of parties by a defendant.
(3) The court may without an application add a new party to proceedings if —
(a) it is desirable to add the new party so that the court can resolve all the matters in dispute in the proceedings; or
(b) there is an issue involving the new party which is connected to the matters in dispute in the proceedings and it is desirable to add the new party so that the court can resolve that issue.
(4) The court may order any person to cease to be a party if it considers that it is not desirable for that person to be a party to the proceedings.
(5) The court may order a new party to be substituted for an existing one if the —
(a) court can resolve the matters in dispute more effectively by substituting the new party for the existing party; or
(b) existing party's interest or liability has passed to the new party.
(6) The court may add, remove or substitute a party at the first or any subsequent case management conference.
(7) The court may not add a party (except by substitution) after the first case management conference on the application of an existing party unless that party can satisfy the court that the addition is necessary because of some change in circumstances which became known after the first case management conference.