Order 1, Rule 8 CPC

8. One person may sue or defend on behalf of all in same interest.

(1) Where there are numerous persons having the same interest in one suit,-
(a) one or more of such persons may, with the permission of the Court, sue or be sued, or may defend such suit, on behalf of, or for the benefit of, all persons so interested;
(b) the Court may direct that one or more of such persons may sue or be sued, or may defend such suit, on behalf of, or for the benefit of, all persons so interested.

(2) The Court shall, in every case where a permission or direction is given under sub-rule (1), at the plaintiff’s expense, give notice of the institution of the suit to all persons so interested either by personal service, or, where, by reason of the number of persons or any other cause, such service is not reasonably practicable, by public advertisement, as the Court in each case may direct.

(3) Any person on whose behalf, or for whose benefit, a suit is instituted or defended, under sub-rule (1), may apply to the Court to be made a party to such suit.

(4) No part of the claim in any such suit shall be abandoned under sub-rule (1), and no such suit shall be withdrawn under sub-rule (3), of rule 1 of Order XXIII, and no agreement, compromise or satisfaction shall be recorded in any such suit under rule 3 of that Order, unless the Court has given, at the plaintiff’s expense, notice to all persons so interested in the manner specified in sub-rule (2).

(5) Where any person suing or defending in any such suit does not proceed with due diligence in the suit or defence, the Court may substitute in his place any other person having the same interest in the suit.

(6) A decree passed in a suit under this rule shall be binding on all persons on whose behalf, or for whose benefit, the suit is instituted, or defended, as the case may be.

Explanation-
For the purpose of determining whether the persons who sue or are sued, or defend, have the same interest in one suit, it is not necessary to establish that such persons have the same cause of action as the person on whom behalf, or for whose benefit, they sue or are sued, or defend the suit, as the case may be.

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