Calubaquib-Diaz vs. Diaz

A court acquires no jurisdiction over the person of a defendant in a petition for declaration of nullity of marriage if the service of summons by publication is resorted to without first demonstrating that personal service and substituted service are impossible through diligent and reasonable efforts. The preferred mode is personal service, and a sheriff or process server must make at least three attempts, preferably on two different dates, and detail all efforts in the return. Failure to comply with these stringent requirements renders the service defective, the judgment void, and satisfies neither jurisdictional nor due process requirements.

Petitioner Kristine Calubaquib-Diaz and respondent Dino Lopez Diaz were married on June 28, 2010, and had a son. The petitioner alleged that the respondent exhibited psychological incapacity through consistent neglect, infidelity, failure to support the family, and a lack of commitment to marital obligations. The respondent left the conjugal home in late 2012. On May 2, 2013, the petitioner filed a Petition for Declaration of Nullity of Marriage under Article 36 of the Family Code before the Regional Trial Court of Quezon City.

• Nature of the Action: Petitioner filed a Petition for Declaration of Nullity of Marriage under Article 36 of the Family Code, alleging the respondent's psychological incapacity.
• Service Attempts and Resort to Publication: The process server attempted to serve summons at the address provided on May 24, 2013, and June 10, 2013. On both occasions, the security guard stated the respondent only visited occasionally and was residing in Antipolo City. The process server returned the summons unserved. Petitioner then filed a motion for alias summons and for leave to serve by publication, which the RTC granted.
• RTC Proceedings and Decision: After publication and a prosecutor's finding of no collusion, trial proceeded with only the petitioner presenting evidence. The RTC rendered a decision declaring the marriage null and void, awarding custody of the child to the petitioner, and ordering support.
• CA Reversal: The OSG appealed. The CA found the service of summons fatally defective. It held the process server's two attempts were insufficient and that the information from the security guard (that respondent visited occasionally and lived in Antipolo) was a vital lead that should have been pursued. The immediate resort to publication without attempting substituted service or further investigation failed to meet the standard of diligent effort, depriving the RTC of jurisdiction over the respondent's person.
• Supreme Court Petition: Petitioner argued the CA erred, claiming the attempts were diligent, publication was proper, and the OSG was estopped from questioning jurisdiction.

• Propriety of Summons by Publication: Petitioner argued that the two attempts at personal service, coupled with the security guard's information that the respondent only visited occasionally and resided in Antipolo City, demonstrated the impossibility of personal service and justified the immediate resort to publication.
• Jurisdiction Over the Res: Petitioner maintained that in actions in rem like nullity of marriage, the court acquires jurisdiction through the filing of the petition and control over the res (the marital bond). The purpose of summons is merely to satisfy due process, not to vest jurisdiction.
• Estoppel: Petitioner asserted that the OSG was estopped from questioning the court's jurisdiction over the respondent's person because it failed to oppose the motion for publication at the earliest opportunity, having been furnished copies of the motions and orders.

• Jurisdictional Requirement in All Actions: The OSG countered that jurisdiction over the parties is required regardless of the type of action (in personam, in rem, or quasi in rem) to satisfy due process.
• Failure of Diligent Effort: The OSG argued that the process server did not exert genuine effort. The "three attempts rule" from Manotoc v. Court of Appeals must be strictly observed, and two attempts are insufficient. The process server failed to investigate the lead about the respondent's residence in Antipolo or attempt substituted service.
• No Estoppel on Jurisdiction: The OSG contended that the issue of jurisdiction over the person can be raised at any stage and cannot be waived by estoppel, especially where, as here, the respondent was never properly notified of the proceedings.

• Service of Summons: Whether the service of summons by publication upon the respondent was valid, thereby vesting the Regional Trial Court with jurisdiction over his person.
• Estoppel: Whether the Office of the Solicitor General is estopped from questioning the trial court's jurisdiction over the person of the respondent.

• Service of Summons: The service by publication was invalid. The process server made only two inadequate attempts at personal service. The return showed the respondent frequented the given address and that a specific lead (residence in Antipolo City) was provided but not pursued. Petitioner immediately sought publication without attempting substituted service or explaining its infeasibility. This failed to comply with the strict, mandatory requirements for alternative modes of service, rendering the service defective and the trial court without jurisdiction over the respondent's person.
• Estoppel: The OSG is not estopped. The rule that objections to jurisdiction must be raised at the earliest opportunity presupposes that the party has been properly notified of the proceedings. Since the respondent was never validly served with summons, he had no "earliest possible opportunity" to raise the issue. The OSG's failure to object earlier is irrelevant where the foundational defect is the lack of jurisdiction over the person of the respondent.

• Doctrine on Service of Summons and Jurisdiction — Jurisdiction over the person of the defendant is acquired through valid service of summons or voluntary appearance. This is required in all types of actions (in personam, in rem, quasi in rem) to satisfy due process. Personal service is the preferred mode. Substituted service or service by publication may only be resorted to after strict compliance with procedural safeguards: demonstrating the impossibility of personal service through diligent efforts (at least three attempts on different dates), detailing those efforts in the return, and, for publication, showing that even substituted service is unavailing and the defendant's whereabouts are unknown despite diligent inquiry. Non-compliance renders the service void and the judgment a nullity.

• "Regardless of the type of action — whether it is in personam, in rem, or quasi in rem — the preferred mode of service of summons is personal service. If parties resort to other modes of service, the sheriffs or the process server's return must detail the actions taken and show that the other party cannot be personally served despite diligent and reasonable efforts." — This passage establishes the overarching principle governing the hierarchy and requirements for service of summons.
• "Petitioner's act of immediately asking for leave of court to effect service through publication, instead of chasing down the lead regarding respondent's current address or availing of substituted service of summons, reveals her deliberate intent to bypass respondent's due process rights and keep him in the dark regarding the petition to annul their marriage." — This excerpt highlights the Court's finding of bad faith and the critical link between procedural shortcuts and the denial of due process.

• De Pedro v. Romasan Development Corporation, 748 Phil. 706 (2014) — Cited as controlling authority on the principle that jurisdiction over the parties is required in all types of actions to satisfy due process, and that strict compliance with rules on service of summons is imperative.
• Manotoc v. Court of Appeals, 530 Phil. 454 (2006) — Applied and reaffirmed. This case established the "three attempts rule" for personal service and the requirement that the sheriff's return must detail the efforts made to locate the defendant. The Court distinguished the present case from Macasaet v. Co, Jr., where a third attempt was deemed futile.
• Macasaet v. Co, Jr., 710 Phil. 167 (2013) — Distinguished. The Court noted that in Macasaet, the sheriff was informed during the second attempt that there was no likelihood of the respondent's return, making a third attempt futile. In the present case, the process server was given a lead (Antipolo residence) that warranted further investigation.

• Rule 14, Sections 6, 7, and 16 of the Rules of Court — These provisions govern personal service, substituted service, and service by publication, respectively. The Court applied them strictly, holding that the petitioner failed to comply with the conditions precedent (diligent attempts at personal and substituted service) required before resorting to publication under Section 16.
• Article 36 of the Family Code — The substantive law under which the petition for nullity was filed. The Court's ruling did not delve into the merits of the psychological incapacity claim due to the fatal procedural defect.

• Justice Amy C. Lazaro-Javier
• Justice Henri Jean Paul B. Inting (as Acting Member per Raffle dated July 18, 2022)
• Justice Jhosep Y. Lopez
• Justice Antonio T. Kho, Jr.