See - G.R. No. 153059
"x x x.
Notably, however, while PepsiCo was properly impleaded as a party defendant, Pizza Hut, an indispensable party, was not. An indispensable party is a party-in-interest without whom no final determination can be had of an action, and who shall be joined either as plaintiff or defendant.30 The joinder of indispensable parties is mandatory. Their presence is necessary to vest the court with jurisdiction, which is "the authority to hear and determine a cause, the right to act in a case." Thus, without their presence to a suit or proceeding, judgment of a court cannot attain real finality. The absence of an indispensable party renders all subsequent actions of the court null and void for want of authority to act, not only as to the absent parties but even as to those present.31
Nevertheless, the non-joinder of indispensable parties is not a ground for the dismissal of an action, and the remedy is to implead the non-party claimed to be indispensable. Parties may be added by order of the court on motion of the party or on its own initiative at any stage of the action and/or at such times as are just.32 If the petitioner refuses to implead an indispensable party despite the order of the court, the latter may dismiss the complaint/petition for the plaintiff/petitioner's failure to comply therewith.33
Hence, as no final ruling on this matter can be had without impleading Pizza Hut, its inclusion is necessary for the effective and complete resolution of the case and in order to accord all parties the benefit of due process and fair play.34
x x x."