How to Acquire Jurisdiction over the Defendant

[1] Jurisdiction over the person of the defendant is required only in an action in personam; it is not a prerequisite in an action in rem or quasi in rem. In an action in personam, jurisdiction over the person is necessary for the court to validly try and decide the case, while in a proceeding in rem or quasi in rem, jurisdiction over the person of the defendant is not a prerequisite to confer jurisdiction on the court, provided the latter has jurisdiction over the res.
[2] By voluntary appearance of the defendant, jurisdiction over the defendant is acquired by the court even without service of summons or despite a defective service of summons. The defendant‘s voluntary appearance in the action shall be equivalent to service of summons.
[3] The following are instances when the appearance of the defendant is not equal to voluntary submission to the jurisdiction of the court:

          (a) when defendant files the necessary pleading;
          (b) when defendant files motion for reconsideration of the judgment by default;
          (c) when defendant files a petition to set aside the judgment of default;
          (d) when the parties jointly submit a compromise agreement for approval of the court;
          (e) when defendant files an answer to the contempt charge;
          (f) when defendant files a petition for certiorari without questioning the court‘s jurisdiction over his person.

[4] A defendant who files a motion to dismiss, assailing the jurisdiction of the court over his person, together with other grounds raised therein, is not deemed to have appeared voluntarily before the court. What the rule on voluntary appearance means is that the voluntary appearance of the defendant in court is without qualification, in which case he is deemed to have waived his defense of lack of jurisdiction over his person due to improper service of summons (Lhuillier vs. British Airways). [5] The filing of a motion for time is considered a submission to the jurisdiction of the court. A party who makes a special appearance in court challenging the jurisdiction of said court on the ground of invalid service of summons is not deemed to have submitted himself to the jurisdiction of the court (UCPB vs. Ongpin).
[5a] In this case, however, although the Motion to Dismiss filed specifically stated as one (1) of the grounds lack of personal jurisdiction, it must be noted that defendant had earlier filed a Motion for Time to file an appropriate responsive pleading even beyond the time provided in the summons by publication. Such motion did not state that it was a conditional appearance entered to question the regularity of the service of summons, but an appearance submitting to the jurisdiction of the court by acknowledging the summons by publication issued by the court and praying for additional time to file a responsive pleading. Consequently, defendant having acknowledged the summons by publication and also having invoked the jurisdiction of the trial court to secure affirmative relief in his motion for additional time, he effectively submitted voluntarily to the trial court‘s jurisdiction. He is now estopped from asserting otherwise, even before tis Court (Go vs. Cordero).
[6] A special appearance before the court challenging its jurisdiction over the person through a motion to dismiss even if the movant invokes other grounds is not tantamount to estoppel or a waiver by the movant of his objection to jurisdiction over his person; and such is not constitutive of a voluntary submission to the jurisdiction of the court (Kukan International Corp. v. Reyes).