Updated for the Family Code framework and later amendments (e.g., R.A. 9255 and R.A. 9858). This article is doctrinal and practical, aimed at parents, counsel, and civil registrars.

1) What is “legitimation by subsequent marriage”?

Legitimation is the legal process by which a child conceived and born out of wedlock becomes legitimate because the child’s parents subsequently marry each other. Under the Family Code of the Philippines (EO 209), legitimation is by operation of law once a valid marriage between the biological parents takes place, provided legal conditions are met. The civil-registry paperwork is declaratory, not constitutive; it records a status that the law already confers.

2) Statutory backbone (quick map)

Arts. 177–182, Family Code — who may be legitimated; mode (subsequent valid marriage); retroactive effect; challenge/impugnation.
Art. 176, Family Code (as amended by R.A. 9255) — baseline rights of illegitimate children (surname, parental authority with the mother, etc.) before legitimation.
R.A. 9858 (2010) — expanded legitimation to cover children whose parents’ only impediment to marry at conception/birth was minority (below 18).
Arts. 209–213, Family Code — parental authority and custody rules for legitimate children; tender-age doctrine (under 7 not to be separated from the mother absent compelling reasons).
Arts. 887 et seq., Civil Code/Family Code — succession: legitime of legitimate vs. illegitimate children.

3) Who can be legitimated?

A child may be legitimated if, at the time of conception, the parents could have married each other (i.e., no impediment other than minority, which is now forgiven by R.A. 9858), and the parents later contract a valid marriage with each other.

3.1 Permissible scenarios

Both single at conception/birth → later validly marry each other.
One or both were under 18 (minority) at conception/birth → later validly marry each other after reaching capacity (R.A. 9858 cures the age impediment).

3.2 Non-permissible (“illegitimate but not capable of legitimation”)

If there was a diriment impediment between the parents at conception (and not merely age), the child is not capable of legitimation by their later marriage. Classic examples:

One parent was validly married to a third person (bigamy/adultery context).
Incestuous relationship.
Other void/voidable impediments that made marriage between the parents legally impossible at conception.

Key point: The validity of the later marriage also matters. A void subsequent marriage does not legitimate.

4) How and when does legitimation take effect?

Automatically upon the parents’ valid marriage to each other.
Retroacts to the child’s birth (Family Code): once legitimated, the child is deemed legitimate from birth for all purposes (status, surname, support, succession, parental authority).

4.1 Civil-registry recording (practical steps)

While the effect is automatic, you should regularize the records:

Prepare an Affidavit of Legitimation signed by both parents (or by the surviving/available parent in line with civil-registry rules).
File with the Local Civil Registrar (LCR) of the place of birth or where the birth was recorded; the LCR forwards to the Philippine Statistics Authority (PSA).
The birth record is annotated to reflect legitimation; the child’s status becomes “legitimate” and the surname updates accordingly.
If the child is already an adult, obtain his/her consent when required by LCR practice (not a condition to the status, but part of paperwork hygiene).

Tip: For school, passport, GSIS/SSS/PhilHealth, and estate planning, promptly secure the PSA-certified annotated birth certificate showing legitimation.

5) Immediate legal effects of legitimation

Status: Child becomes legitimate (retroactive to birth).
Surname: Child bears the father’s surname as a legitimate child (superseding the R.A. 9255 framework that applied when the child was illegitimate).
Filiation: Becomes legitimate filiation; evidentiary presumptions for legitimate children now apply.
Parental authority: Shifts from mother alone (the default for an illegitimate child) to both parents jointly (Arts. 209–211 FC).
Support: Right to full support from both parents (already existed, but classification now as legitimate).
Succession: Receives the legitime of a legitimate child (in full equality with other legitimate children), including rights vis-à-vis legitimate collateral relatives.
Property relations: Any donations, insurance designations, beneficiary statuses, and family-home considerations that differentiate between legitimate and illegitimate offspring now treat the child as legitimate from birth.

6) Custody and parental authority where parents are separated

“Separated” can mean several different things in practice. The rules differ depending on when the separation occurs and the legal status of the parents’ relationship at that time.

6.1 Before the parents marry each other (child still illegitimate)

Parental authority is with the mother (Art. 176 FC).
The father has no custodial right as a matter of course, but may seek reasonable visitation; custody requires showing the mother is unfit or that the best interests of the child demand otherwise (doctrinally affirmed in case law).
Child under seven (7): Tender-age doctrine still guides courts; do not separate from the mother absent compelling reasons (e.g., abuse, neglect, grave unfitness).

Practical upshot: If the parents are separated and unmarried, the mother is the default custodian. Written co-parenting arrangements are enforceable only insofar as they track the best-interests standard and cannot waive the child’s rights.

6.2 After the parents marry each other (child becomes legitimate by legitimation)

Parental authority becomes joint (Arts. 209–211 FC).
Custody is shared; day-to-day residence should follow a mutually agreed parenting plan. Disputes are resolved under the best interests of the child standard.

If the parents later separate (de facto) or obtain a decree (legal separation, annulment, or nullity):

No automatic loss of parental authority for either parent.
Courts decide custody based on best interests, considering: age, health, stability, history of caregiving, schooling, presence of siblings, violence/abuse, substance issues, each parent’s willingness to foster the child’s relationship with the other, etc.
Under 7 years old: strong presumption not to separate from the mother without compelling reasons (Art. 213 FC).
Protective orders and criminal law (e.g., VAWC under R.A. 9262) may override default custody arrangements to protect the child.

Travel & school decisions after legitimation:

As with other legitimate children, major decisions require both parents’ consent (or a court order allocating decision-making). For international travel, immigration and DSWD practice generally look for the non-traveling parent’s consent or a court order when joint parental authority exists.

7) Special problem sets

7.1 Void or voidable subsequent marriage

Void marriage between the parents does not produce legitimation.
Voidable marriage (e.g., lack of parental consent, psychological incapacity) does produce legitimation until annulled; if annulled, the prior legitimation is generally not unwound because the statute confers status at marriage and retroacts to birth; however, edge cases can arise if the marriage is judicially declared void ab initio versus annulled.

7.2 One parent dies before the marriage

No legitimation by “what might have been.” Without a subsequent valid marriage, legitimation does not occur. Consider adoption as a functional substitute for creating full legitimacy-equivalent ties for succession and authority.

7.3 Bigamous/adulterous conceptions

If at conception one parent was married to someone else, the child is incapable of legitimation by the later inter se marriage of the biological parents (unless and until the legal impediment at conception is within the class cured by statute—which it is not). The child remains illegitimate, though filiation and support rights subsist; surname may be addressed via R.A. 9255 if requirements are met.

7.4 Assisted reproduction and filiation proofs

The Family Code’s legitimation framework presumes biological filiation. Where assisted reproduction complicates proof, courts still require clear evidence of filiation to trigger legitimation effects.

8) How can legitimation be challenged?

Legitimation may be impugned only on grounds akin to impugning legitimacy (e.g., lack of access/non-paternity, invalidity of the subsequent marriage). Typical challengers: the husband/father within statutory periods, or, in limited settings, heirs where the action survives or lies by express rule. Strict periods and burdens of proof apply; courts are protective of status once vested.

9) Interplay with support, visitation, and protection laws

Support (financial) is independent of custody and status disputes; both legitimate and illegitimate children are entitled to support proportionate to the parents’ resources and the child’s needs.
Visitation/contact orders are crafted around best interests; even where the mother has sole authority (pre-legitimation), courts may structure liberal visitation for a fit father.
Protective statutes (e.g., R.A. 9262 on violence against women and their children) can curtail custody/visitation notwithstanding joint authority after legitimation.

10) Practical timelines and checklists

Before the marriage (child illegitimate)

Mother has sole parental authority.
Father may recognize the child (for support/visitation; may enable R.A. 9255 surname use).
Consider a co-parenting agreement (soft-law unless court-approved).

On/after the parents’ valid marriage

Legitimation attaches automatically; retroacts to birth.
File Affidavit of Legitimation with the LCR/PSA; update school, bank, and government records.

If parents are (or become) separated after marriage

Treat as a legitimate child custody case:
- Try mediation and a written parenting plan (schedules, holidays, decision-making, relocation rules, expense-sharing).
- If litigation is necessary, plead best interests factors; remember tender-age presumption under Art. 213.
- Secure interim relief (temporary custody/support, protection orders) where needed.

11) Alternatives if legitimation is not legally available

Adoption by the parent’s spouse (or by both parents if eligible) to achieve full legitimate status effects.
Maintain filiation via acknowledgment and pursue support and visitation orders; consider R.A. 9255 for surname use if requirements are met.
Estate planning (wills, insurance, inter vivos donations) to mitigate succession disparities.

12) Frequently asked tight answers

Q: We are separated (not married to each other). Do I, the father, get custody now? A: No. Before marriage, the child is illegitimate; mother has sole parental authority. You can seek visitation; custody requires showing mother’s unfitness or other best-interests grounds.

Q: We later married each other. Are we both now custodians? A: Yes. Your marriage legitimated the child; parental authority is joint. If you then separate, custody is decided as for legitimate children under best interests, with tender-age considerations.

Q: Our later marriage was declared void. What happens to legitimation? A: A void marriage does not legitimate. If voidness was declared after you relied on it, you will need counsel; outcomes turn on whether the marriage was void ab initio and the specific grounds.

Q: One of us was married to someone else when our child was conceived. We later married each other after that prior marriage ended. Legitimation? A: No. Because there was a marital impediment at conception, the child is not capable of legitimation by your later marriage.

13) Counsel’s notes & advocacy angles

Document filiation early (acknowledgment, DNA if needed) to avoid later evidentiary fights.
In custody disputes, lead with a child-focused plan: routines, schooling, healthcare, and the child’s voice (age-appropriate).
For international families, align Philippine status records with foreign documents to avoid travel and immigration friction.
In estate planning, re-audit beneficiary designations post-legitimation.

14) Bottom line

Legitimation by subsequent valid marriage transforms a child’s status retroactively to birth and shifts custody from mother-alone to joint parental authority.
Where parents are separated, custody after legitimation is resolved under the best interests of the child, with the tender-age doctrine as a strong but rebuttable guide.
If legitimation is unavailable (e.g., impediment at conception), consider adoption and robust co-parenting orders to protect the child’s welfare.

Disclaimer

This article is an educational overview of Philippine law. For fact-sensitive advice and document preparation (e.g., Affidavit of Legitimation, parenting plans, or court pleadings), consult counsel and your Local Civil Registrar.