(Family Code and key jurisprudence, with practical litigation notes)

1) Start with the right legal label: “nullity” vs “annulment”

In Philippine family law, there are two main ways a marriage is judicially “undone,” and the grounds matter because the rules, timelines, and effects differ:

A. Declaration of Nullity (Void Marriage)

A marriage is treated as void from the beginning (void ab initio)—as if no valid marriage existed—but a court judgment is still required before parties may validly remarry.

Common grounds are under Family Code Articles 35, 36, 37, and 38, including:

Lack of essential/requisite formalities (e.g., no authority of solemnizing officer in certain cases)
Psychological incapacity (Art. 36)
Incestuous marriages (Art. 37)
Void by reason of public policy (Art. 38)

B. Annulment (Voidable Marriage)

A marriage is valid until annulled. It can be “cured” by ratification in some cases, and it is subject to prescriptive periods.

Grounds are under Family Code Article 45, including:

Lack of parental consent (certain ages)
Unsound mind (mental incapacity in the traditional sense)
Fraud
Force, intimidation, undue influence
Physical incapacity to consummate
Serious and incurable STD

Key point for this topic:

Fraud is not a ground for nullity; it is a ground for annulment (voidable marriage).
Mental incapacity can appear in two different legal forms:
1. Unsound mind at the time of marriage (annulment, Art. 45[2])
2. Psychological incapacity to comply with essential marital obligations (nullity, Art. 36)

So, when people say “nullify due to fraud and mental incapacity,” they’re often mixing grounds that belong to different legal remedies.

2) Fraud as a ground to set aside the marriage (Annulment)

2.1 Legal basis

Family Code, Article 45(3): A marriage may be annulled if consent was obtained by fraud, as defined in Article 46.
Family Code, Article 46: Enumerates what counts as fraud for annulment purposes.
Family Code, Article 47: Provides who may file and the prescriptive period.

2.2 What “fraud” means here (and what it does not mean)

In ordinary language, fraud is broad. In annulment law, fraud is narrowly defined. Only specific kinds of deception qualify—generally those that go to the essentials of marital consent.

Fraud that can qualify (typical Art. 46 categories):

Non-disclosure of a previous conviction by final judgment of a crime involving moral turpitude
Concealment of pregnancy by another man at the time of marriage
Concealment of a sexually transmissible disease that is serious and appears incurable
Concealment of drug addiction, habitual alcoholism, or homosexuality/lesbianism existing at the time of marriage (as historically recognized under the Family Code’s text and interpretation)

The common thread: the deception must relate to a circumstance so significant that, had it been disclosed, the other party would not have consented to marry.

Not “fraud” for annulment (explicitly excluded):

Misrepresentation as to character, habits, “attitude,” temperament
Misrepresentation as to rank, fortune, social status
Many forms of lying that are painful but not among the legally recognized types
Post-marriage discoveries that were not present at the time of marriage (generally)

2.3 Essential elements you must prove

To annul a marriage on fraud, you typically need evidence of:

A qualifying fraudulent act or concealment existing at the time of marriage
The deception induced consent (the spouse would not have married if truth were known)
The petitioner did not freely cohabit with the other spouse after discovering the fraud (because cohabitation after discovery can be treated as ratification in many fraud-based scenarios)

2.4 Who can file, and when (prescription)

Only the injured party (the spouse whose consent was vitiated) may file.

Deadline: generally within five (5) years from discovery of the fraud.

Missing the deadline is often fatal unless another ground exists.

2.5 Evidence and proof: what courts look for

Fraud cases are fact-heavy. Useful proof can include:

Certified true copies of criminal records and proof of finality (for concealment of conviction)
Medical records and testimony (for STD claims) with careful privacy handling
Prenatal records, timelines, or DNA-related proof (for concealed pregnancy by another)
Treatment history, rehab records, credible witness testimony (for addiction/alcoholism), plus proof it existed before marriage
Admissions in messages, sworn statements, or credible testimony corroborated by independent evidence

Courts are careful because annulment is not meant to be an “exit option” for ordinary marital disappointment.

2.6 Typical defenses against a fraud petition

Not a legally recognized fraud under Art. 46
No causal link to consent (petitioner would have married anyway)
Prescription (filed beyond 5 years from discovery)
Ratification (continued cohabitation after discovery)
Weak or purely testimonial proof without corroboration

3) “Mental incapacity” in two different senses: annulment vs nullity

People use “mental incapacity” loosely. Philippine law separates it into two distinct doctrines:

A. Unsound mind at the time of marriage (Annulment)

3.1 Legal basis

Family Code, Article 45(2): Marriage may be annulled if either party was of unsound mind at the time of marriage.
Family Code, Article 47: Who may file and deadlines.

3.2 What counts as “unsound mind”

This is closer to classic mental incapacity: a party’s mental condition is such that they could not validly give consent or understand the nature and consequences of marriage at the time it was solemnized.

It can include severe mental illness or cognitive impairment, depending on proof. The focus is time-of-marriage capacity.

3.3 Who can file and when

Possible petitioners include:

The sane spouse who was married to the person of unsound mind
The relative/guardian of the party of unsound mind (in certain circumstances)
The party who was of unsound mind may file after regaining sanity (depending on the fact pattern)

Deadline: typically within five (5) years from the time the right to file accrues (often tied to regaining sanity or cessation of the incapacity, depending on who files and why).

3.4 Proof and evidence

Courts usually expect:

Psychiatric/psychological evaluation and expert testimony
Medical history proximate to the wedding (or strong retrospective evaluation anchored on records)
Testimony from people who observed the person before, during, and after the marriage
Evidence showing incapacity affected consent at the time of marriage

Practical note: while expert testimony is highly persuasive, courts also weigh behavior, contemporaneous medical records, and credible lay testimony.

3.5 Common defenses

The party was functional and understood the marriage
The condition was not severe enough to negate consent
Evidence is purely retrospective, speculative, or unsupported by records
Prescription

B. Psychological incapacity (Nullity under Article 36)

This is the most litigated “mental” ground and the one people usually mean when they say “nullify.”

3.6 Legal basis

Family Code, Article 36: A marriage is void if, at the time of marriage, either party was psychologically incapacitated to comply with the essential marital obligations of marriage, even if the incapacity becomes manifest only after marriage.

3.7 What psychological incapacity is—and is not

It is not mere marital difficulty, immaturity, stubbornness, infidelity by itself, incompatibility, or refusal to change. Courts require a condition that makes a spouse truly incapable (not just unwilling) to perform essential marital duties.

The Supreme Court’s doctrine has evolved. The modern view (especially after Tan-Andal v. Andal (2021)) emphasizes:

Psychological incapacity is a legal concept, not strictly a medical diagnosis.
A clinical diagnosis can help, but it is not always indispensable if the totality of evidence shows true incapacity.
The incapacity must be shown to have existed at the time of marriage (even if it only became obvious later).
The focus is on inability to assume essential marital obligations (e.g., mutual love, respect, fidelity, support, cohabitation, and commitment to partnership and family life).

Earlier cases like Republic v. Molina imposed structured “guidelines” often treated strictly by lower courts; later jurisprudence (including Marcos v. Marcos and culminating in Tan-Andal) clarified that the approach should not be a rigid checklist and must be faithful to the statutory language and evidence.

3.8 Essential marital obligations (what incapacity relates to)

Courts generally connect incapacity to the core obligations under the Family Code (and related provisions), such as:

Mutual love, respect, and fidelity
Mutual help and support
Living together (subject to lawful exceptions)
Joint responsibility for family life and children
Capacity for commitment, empathy, and partnership

The incapacity must be such that the spouse cannot genuinely comply in a sustained, meaningful way.

3.9 Typical factual patterns alleged under Article 36

These aren’t automatic wins; they become grounds only when proven as manifestations of a deeper incapacity existing at marriage:

Severe personality dysfunction leading to chronic lying, manipulation, inability to empathize, or inability to commit
Repeated, entrenched abuse patterns tied to psychological dysfunction
Extreme pathological dependency, impulsivity, or irresponsibility that defeats marital partnership
Longstanding incapacity to maintain fidelity/support due to underlying psychological structure, not mere choice

3.10 Evidence and proof: building an Article 36 case

Common components:

Petitioner’s testimony narrating patterns from courtship to marriage to breakdown
Corroborating witnesses (family, friends, co-workers) with specific examples
Documents (messages, police blotters, medical records, employment records, proof of abandonment, financial records)
Expert evaluation (psychologist/psychiatrist), often including:
- Clinical interview with petitioner
- Attempted interview with respondent (sometimes refused)
- Psychological tests and collateral interviews
- A report linking behaviors to incapacity existing at the time of marriage, and explaining how it prevents compliance with essential obligations

After Tan-Andal, expert testimony is still very helpful, but courts may accept other strong evidence showing the legal standard is met.

3.11 Who can file and is there a deadline?

Either spouse may file a petition for declaration of nullity under Article 36.

Prescription: generally, actions to declare a void marriage are treated as not barred by prescription in the same way voidable marriages are—though procedural and equitable considerations still matter. (Practically: delay does not automatically defeat the case, but it can affect credibility and the evidence.)

4) Choosing the correct remedy when fraud and “mental issues” overlap

Sometimes a case has both deception and incapacity-like behavior. The proper approach is to match facts to the right ground:

When fraud fits best (annulment)

Choose annulment for fraud when:

The deception is one of the enumerated Art. 46 types, and
You can prove inducement of consent, and
You are within 5 years of discovery, and
There was no ratification by cohabitation after discovery

When unsound mind fits best (annulment)

Choose annulment for unsound mind when:

The spouse lacked mental capacity to consent at the wedding, and
Evidence shows inability to understand marriage at that time

When psychological incapacity fits best (nullity)

Choose nullity under Art. 36 when:

The core problem is a spouse’s inability (not mere refusal) to perform essential obligations,
Traceable to a condition existing at the time of marriage, and
Demonstrable through credible narrative, corroboration, and (ideally) expert analysis

Can you plead multiple grounds?

Yes, petitions sometimes allege alternative or multiple causes of action (subject to rules and the court’s directions). However, courts are wary of scattershot pleading. The facts must genuinely support each ground, and proof burdens remain.

5) Procedure in the Philippines: what “nullification/annulment” litigation generally looks like

Whether annulment (fraud/unsound mind) or nullity (Art. 36), cases follow a specialized process:

5.1 Where filed

Regional Trial Court (Family Court) with proper venue (typically where the petitioner has been residing for the required period under procedural rules, or where the respondent resides, depending on the rule applied).

5.2 The State participates

Because marriage is imbued with public interest:

The Office of the Solicitor General (OSG) represents the State in nullity/annulment proceedings (especially for nullity).
A public prosecutor may be assigned to ensure no collusion.

5.3 Key stages

Filing of verified petition (with required allegations, marriage certificate, birth certificates of children, etc.)
Summons/service or publication (if respondent cannot be located)
Pre-trial (marking of evidence, stipulations, issues)
Trial (presentation of petitioner, witnesses, expert)
OSG/prosecutor participation; possible cross-examination
Decision
Finality, then registration of the decree with the local civil registrar and PSA for annotation

5.4 Time and difficulty drivers (practical, not promises)

Outcomes often hinge on:

Quality and credibility of evidence
Cooperation/appearance of respondent
Strength of expert testimony (especially for Art. 36)
Docket congestion and hearings schedule
OSG posture (active contest vs limited participation)

6) Effects of a decree: property, children, and remarriage

6.1 Remarriage

Even if a marriage is void, you generally cannot remarry safely without a court decree declaring nullity (to avoid bigamy risk and civil registry problems).

6.2 Children

Children conceived or born in a marriage later declared void may still be legitimate in specific situations (notably where the marriage is void due to Art. 36 or certain void causes and the law treats them as legitimate under the Family Code provisions on legitimacy and presumed validity, depending on the ground).
Legitimacy issues are technical and depend on the exact ground and facts; courts and civil registries treat this carefully.

6.3 Property relations

In void marriages, property regimes may be governed by rules on co-ownership or special property relations for unions in fact.
In annulment (voidable marriages), property relations are addressed upon decree, including liquidation under the applicable property regime and rules on presumptive legitimes and obligations.

6.4 Donations, benefits, and inheritance

Donations by reason of marriage may be revoked depending on the ground and the decree.
Successional rights can change, especially if the marriage is treated as void ab initio.

Because these consequences are fact-specific, decrees often include directives on:

Liquidation of property regime
Custody/parental authority arrangements (if minor children)
Support orders
Civil registry annotation

7) Litigation strategy notes: what usually makes or breaks these cases

Fraud (Annulment)

Strong cases: clear Art. 46 category + documentary proof + timely filing + no ratification. Weak cases: deception is about personality/finances/status; purely testimonial; filed late; continued cohabitation after discovery.

Unsound mind (Annulment)

Strong cases: contemporaneous medical history, hospitalization records, credible expert opinion tied to wedding date, clear inability to consent. Weak cases: ordinary depression/anxiety without consent-impairing severity; speculative retrospective opinions without anchors.

Psychological incapacity (Nullity)

Strong cases: consistent narrative from courtship onward, corroboration, pattern evidence, credible expert linkage to incapacity existing at marriage, and a clear explanation of inability (not just refusal). Weak cases: “we were incompatible,” “he cheated,” “she’s selfish,” with no demonstrated incapacity structure; conclusory expert reports; lack of corroboration.

8) Quick reference guide

If your ground is fraud

Remedy: Annulment (Art. 45[3], 46)
Deadline: 5 years from discovery
Must be Art. 46-type fraud
Ratification risk: cohabitation after discovery

If your ground is unsound mind

Remedy: Annulment (Art. 45[2])
Deadline: generally 5 years depending on who files and when capacity is regained/issue becomes actionable
Focus: capacity to consent at the time of marriage

If your ground is psychological incapacity

Remedy: Declaration of Nullity (Art. 36)
Deadline: generally not treated like a strict prescriptive period
Focus: legal incapacity to comply with essential marital obligations, existing at marriage (even if later manifested)

9) Closing reminder

These cases are decided on precise statutory grounds and proof, not on general unfairness or marital failure. Correctly classifying the facts into fraud (annulment), unsound mind (annulment), or psychological incapacity (nullity) is the foundation of any successful petition.

If you want, I can also provide:

A sample outline of a petition’s key allegations for each ground (fraud vs unsound mind vs Art. 36), or
A checklist of evidence commonly used per ground, organized by what courts usually find persuasive.