Joinder of Parties
 5.02 (1) Two or more persons who are represented by the same lawyer of record may join as plaintiffs or applicants in the same proceeding where, (a) they assert, whether jointly, severally or in the alternative, any claims to relief arising out of the same transaction or occurrence, or series of transactions or occurrences; (b) a common question of law or fact may arise in the proceeding; or (c) it appears that their joining in the same proceeding may promote the convenient administration of justice.  R.R.O. 1990, Reg. 194, r. 5.02 (1); O. Reg. 575/07, s. 9. Multiple Defendants or Respondents (2) Two or more persons may be joined as defendants or respondents where, (a) there are asserted against them, whether jointly, severally or in the alternative, any claims to relief arising out of the same transaction or occurrence, or series of transactions or occurrences; (b) a common question of law or fact may arise in the proceeding; (c) there is doubt as to the person or persons from whom the plaintiff or applicant is entitled to relief; (d) damage or loss has been caused to the same plaintiff or applicant by more than one person, whether or not there is any factual connection between the several claims apart from the involvement of the plaintiff or applicant, and there is doubt as to the person or persons from whom the plaintiff or applicant is entitled to relief or the respective amounts for which each may be liable; or (e) it appears that their being joined in the same proceeding may promote the convenient administration of justice.  R.R.O. 1990, Reg. 194, r. 5.02 (2). Joinder of Necessary Parties General Rule 5.03 (1) Every person whose presence is necessary to enable the court to adjudicate effectively and completely on the issues in a proceeding shall be joined as a party to the proceeding.  R.R.O. 1990, Reg. 194, r. 5.03 (1). Claim by Person Jointly Entitled (2) A plaintiff or applicant who claims relief to which any other person is jointly entitled with the plaintiff or applicant shall join, as a party to the proceeding, each person so entitled.  R.R.O. 1990, Reg. 194, r. 5.03 (2). Claim by Assignee of Chose in Action (3) In a proceeding by the assignee of a debt or other chose in action, the assignor shall be joined as a party unless, (a) the assignment is absolute and not by way of charge only; and (b) notice in writing has been given to the person liable in respect of the debt or chose in action that it has been assigned to the assignee.  R.R.O. 1990, Reg. 194, r. 5.03 (3). Power of Court to Add Parties (4) The court may order that any person who ought to have been joined as a party or whose presence as a party is necessary to enable the court to adjudicate effectively and completely on the issues in the proceeding shall be added as a party.  R.R.O. 1990, Reg. 194, r. 5.03 (4). Party Added as Defendant or Respondent (5) A person who is required to be joined as a party under subrule (1), (2) or (3) and who does not consent to be joined as a plaintiff or applicant shall be made a defendant or respondent.  R.R.O. 1990, Reg. 194, r. 5.03 (5). Relief Against Joinder of Party (6) The court may by order relieve against the requirement of joinder under this rule.  R.R.O. 1990, Reg. 194, r. 5.03 (6). Misjoinder, Non-Joinder and Parties Incorrectly Named Proceeding not to be Defeated 5.04 (1) No proceeding shall be defeated by reason of the misjoinder or non-joinder of any party and the court may, in a proceeding, determine the issues in dispute so far as they affect the rights of the parties to the proceeding and pronounce judgment without prejudice to the rights of all persons who are not parties.  R.R.O. 1990, Reg. 194, r. 5.04 (1). Adding, Deleting or Substituting Parties (2) At any stage of a proceeding the court may by order add, delete or substitute a party or correct the name of a party incorrectly named, on such terms as are just, unless prejudice would result that could not be compensated for by costs or an adjournment.  R.R.O. 1990, Reg. 194, r. 5.04 (2). Adding Plaintiff or Applicant (3) No person shall be added as a plaintiff or applicant unless the person’s consent is filed.  R.R.O. 1990, Reg. 194, r. 5.04 (3).