Marriage under Philippine law is a special contract and a social institution that the State protects and promotes as the foundation of the family. The Family Code of the Philippines (Executive Order No. 209, as amended) governs the validity of marriages, including the grounds for declaring a marriage void ab initio—meaning it is considered never to have existed legally. A judicial declaration of absolute nullity is required before parties may remarry, as the marriage produces no legal effects from the beginning. This is distinct from the annulment of a voidable marriage, which is valid until a court decree sets it aside.

The legal framework rests primarily on Articles 35 to 54 of the Family Code, supplemented by the Supreme Court’s Rule on Declaration of Absolute Nullity of Void Marriages and Annulment of Voidable Marriages (A.M. No. 02-11-10-SC, effective March 15, 2003). These rules ensure procedural safeguards to protect the sanctity of marriage, prevent collusion between spouses, and uphold public policy.

Distinction Between Absolute Nullity and Annulment

A void marriage (subject to absolute nullity) is invalid from the moment of celebration and produces no legal effects whatsoever. It may be attacked collaterally in appropriate proceedings, though a direct judicial action is necessary for purposes such as remarriage or property liquidation. In contrast, a voidable marriage (subject to annulment under Article 45) is valid and produces all legal effects until a competent court annuls it. Grounds for annulment include lack of parental consent for parties aged 18 to 21, unsound mind, fraud, force, intimidation, or physical incapacity. Annulment actions prescribe within specific periods (e.g., five years for fraud), while actions for nullity generally do not prescribe, subject only to laches.

Grounds for Declaration of Absolute Nullity

The Family Code enumerates the specific grounds that render a marriage void ab initio.

Article 35 – Marriages Void for Lack of Essential or Formal Requisites
The following are void from the beginning:
(1) Those contracted by any party below eighteen years of age, even with the consent of parents or guardians.
(2) Those solemnized by any person not legally authorized to perform marriages, unless either or both parties believed in good faith that the solemnizing officer had the proper authority.
(3) Those solemnized without a valid marriage license, except those exempted under the preceding provisions (such as marriages under Article 34 involving parties who have lived together as husband and wife for at least five years without any legal impediment).
(4) Those that are bigamous or polygamous and do not fall under Article 41 (remarriage after the presumptive death of the absent spouse).
(5) Those contracted through the mistake of one of the contracting parties as to the identity of the other.
(6) Subsequent marriages that are void under Article 53 (failure to comply with the requirements of liquidation, partition, and distribution of properties and delivery of presumptive legitime before entering a subsequent marriage after a previous marriage is declared void or annulled).

Article 36 – Psychological Incapacity
A marriage is void when one or both parties are psychologically incapacitated to comply with the essential marital obligations at the time of the celebration of the marriage. Psychological incapacity must be: (a) grave, (b) juridically antecedent (existing before the marriage), and (c) incurable or permanent. It refers to a serious psychological disorder that renders the person incapable of fulfilling the duties of marriage, such as mutual love, respect, fidelity, and support. It is not mere difficulty, incompatibility, or refusal to comply; expert testimony from a psychiatrist or clinical psychologist is ordinarily presented, though the totality of evidence—including the behavior of the parties during and after the marriage—may suffice. The incapacity must be proven to be the root cause of the failure of the marriage.

Article 37 – Incestuous Marriages
The following marriages are void by reason of public policy and relationship:
(1) Between ascendants and descendants of any degree, whether legitimate or illegitimate.
(2) Between brothers and sisters, whether of the full or half-blood, legitimate or illegitimate.

Article 38 – Marriages Against Public Policy
The following marriages are void by reason of public policy:
(1) Between collateral blood relatives, whether legitimate or illegitimate, up to the fourth civil degree.
(2) Between step-parents and step-children.
(3) Between parents-in-law and children-in-law.
(4) Between the adopting parent and the adopted child.
(5) Between the surviving spouse of the adopting parent and the adopted child.
(6) Between the surviving spouse of the adopted child and the adopter.
(7) Between an adopted child and a legitimate child of the adopter.
(8) Between the adopted children of the same adopter.
(9) Between parties where one, with the intention to marry the other, kills the latter’s spouse or his or her own spouse.

Article 40 in Relation to Article 35(4)
A person who wishes to remarry after a previous marriage must first obtain a judicial declaration of nullity or annulment of the prior marriage. Without such declaration, the subsequent marriage is void, even if the first marriage was itself void.

Article 41 – Remarriage After Presumptive Death
A subsequent marriage contracted by a person whose spouse has been absent for four consecutive years (or two years in cases of danger of death) is valid only if there is a prior judicial declaration of presumptive death. If the absent spouse reappears and the second marriage was not terminated properly, the second marriage becomes void.

Other provisions, such as Article 53 (non-compliance with property liquidation before remarriage) and the general rule under Article 4 that the absence of any essential or formal requisite renders the marriage void, complete the statutory grounds.

Procedure for Declaration of Absolute Nullity

The procedure is strictly judicial and designed to protect the institution of marriage.

Who May File
Either spouse may file the petition. In certain cases involving public interest (e.g., bigamy or incest), the State, through the prosecutor, may intervene. Third persons with legal interest (e.g., heirs where property rights are involved) may also file under appropriate circumstances, though the primary parties are the spouses.
Venue and Jurisdiction
The petition is filed with the Regional Trial Court (Family Court) of the place where the petitioner or the respondent has been residing for at least six months prior to the filing. The action is classified as a special proceeding.
Contents of the Petition
The verified petition must allege:
- Personal circumstances of the parties (names, ages, residences).
- Facts constituting the ground(s) for nullity.
- The marriage certificate or proof of marriage.
- Any property regime, children, and other relevant matters.
  The petition must pray for the declaration of nullity, liquidation of properties, custody and support of children (if any), and other reliefs.
Service of Summons and Notice
Summons is served on the respondent. If the respondent cannot be located, service by publication or other substituted service is allowed. The Office of the Solicitor General or the provincial/city prosecutor is furnished a copy and must investigate whether there is collusion between the parties.
Role of the Public Prosecutor
The prosecutor is required to appear and ensure that no collusion exists and that evidence is presented to protect the marriage. Default judgments are not allowed; the petitioner must still prove the case.
Evidence and Hearing
The petitioner bears the burden of proof. For psychological incapacity cases, expert testimony is typically required, supported by documentary and testimonial evidence showing the nature, gravity, and incurability of the condition. The trial proceeds with the presentation of witnesses, cross-examination, and documentary exhibits. The court may appoint an independent expert if necessary.
Judgment
If the court finds the marriage void, it renders a detailed decision declaring the absolute nullity. The decision must include provisions on the liquidation, partition, and distribution of properties; custody and support of children; and other matters. The judgment becomes final only after the lapse of the period for appeal or after the appellate court resolves any appeal.
Finality and Registration
Upon finality, the decree of nullity must be registered with the Local Civil Registrar where the marriage was recorded and with the Philippine Statistics Authority (PSA). Only after registration can either party remarry.

Effects of the Declaration of Absolute Nullity

Once the judgment becomes final and executory:

The marriage is deemed never to have existed legally.
The parties regain their status as single persons and may remarry.
Children conceived or born before the final judgment are considered legitimate (Article 54). Parental authority, custody, support, and visitation rights are determined in the same proceeding or in a subsequent action.
Property relations are governed by the rules on co-ownership (Article 147 or 148, depending on whether the parties are in good faith). The conjugal partnership or absolute community does not apply retroactively.
Any donations or gifts made in consideration of marriage are revoked.
The decree may include orders for support, name restoration, and other equitable reliefs.

Additional Considerations

Actions for nullity are imprescriptible, but the doctrine of laches may bar relief in extreme cases of unreasonable delay. The State policy favors the validity of marriage; courts interpret the grounds strictly and require clear and convincing evidence. The prohibition against collusion ensures that the proceedings are adversarial and not merely consensual. In cases involving foreign marriages or mixed marriages, the national law of the parties or the lex loci celebrationis may apply, subject to Philippine public policy.

The declaration of absolute nullity restores the parties to their pre-marital status and allows them to enter new valid marriages, while safeguarding the rights of children and the orderly liquidation of property. This comprehensive legal regime underscores the State’s commitment to the sanctity of marriage and the protection of the family as the basic unit of society.