1) Core ideas and why the topic matters

In Philippine family law, paternity (who the father is) and filiation (the legal relationship between parent and child) determine a child’s status (legitimate/illegitimate), surname, parental authority, support, and successional rights. Disputes usually arise when a man:

is presumed by law to be the father (typically the husband), but seeks to deny paternity; or
is alleged to be the father (typically a putative father of an illegitimate child), but refuses to recognize the child; or
is the biological father but is blocked by the law’s protection of an existing legitimate family.

Philippine law strongly protects children from being “bastardized” casually. As a result, there are specific actions, strict time limits, and limited persons who can sue—especially when the child is presumed legitimate.

2) The legal framework (main sources)

Family Code of the Philippines (Executive Order No. 209, as amended)
- Legitimacy and presumptions: Arts. 164–171
- Proof and actions for filiation: Arts. 172–176
- Support: Arts. 194–208
Rules of Court
- Support pendente lite (provisional support while case is pending): Rule 61
- Evidence rules applicable to paternity/filiation cases
Rule on DNA Evidence (A.M. No. 06-11-5-SC)
- Court-ordered DNA testing, standards, and evaluation of results
Family Courts Act of 1997 (R.A. 8369)
- Jurisdiction and handling of family cases
Civil Registry laws and procedures
- Judicial correction/cancellation of entries (commonly via Rule 108) where filiation entries must be corrected after a court ruling
R.A. 9255 (use of father’s surname by an illegitimate child)
- Allows an illegitimate child to use the father’s surname if there is acknowledgment under the law

3) Legitimacy vs. illegitimacy: the starting point

A. The presumption of legitimacy (the most important rule)

Under the Family Code, a child conceived or born during a valid marriage is presumed legitimate (Art. 164). This presumption is powerful because it stabilizes the child’s status.

Practical effect: If the mother is married, the law generally treats the husband as the father unless the husband (or, in narrow cases, his heirs) timely files the proper action to contest legitimacy.

B. Why “denial of paternity” is not one-size-fits-all

“Denial of paternity” can mean two very different legal disputes:

Impugning legitimacy (husband contests legitimacy of a child presumed legitimate)
Contesting/denying alleged paternity of an illegitimate child (putative father disputes filiation claims)

The rules, standing to sue, and deadlines differ sharply.

4) Denial of paternity by the husband: the action to impugn legitimacy

A. The only proper vehicle: an action to impugn legitimacy

When a child is presumed legitimate, the husband cannot simply deny paternity informally or incidentally. The Family Code requires a direct action to impugn legitimacy (Arts. 166–171). If the husband does not file the correct case on time, the child’s legitimate status generally becomes legally fixed.

B. Who may file (standing)

The husband is the primary person who may impugn the child’s legitimacy (Art. 170).
The husband’s heirs may file only in exceptional situations (Art. 171), such as:
- the husband dies before the period to file expires;
- the husband files and then dies; or
- the child is born after the husband’s death (and circumstances fit the law’s conditions).

Key limitation: As a rule, third parties (including an alleged biological father) cannot use an impugning action to disrupt an existing legitimate filiation protected by the law.

C. Grounds to impugn legitimacy (Family Code, Art. 166)

Legitimacy may be impugned only on these grounds:

Physical impossibility for the husband to have sexual intercourse with the wife within the relevant conception period because of:
- physical incapacity of the husband;
- living separately such that access was not possible; or
- serious illness of the husband that made intercourse impossible.
Biological or other scientific reasons showing the child could not be the husband’s (commonly DNA evidence), except when the child is conceived through artificial insemination under conditions recognized by law.
For children conceived through artificial insemination, if the required written authorization/ratification was obtained through mistake, fraud, violence, intimidation, or undue influence.

D. Strict filing deadlines (Family Code, Art. 170)

The husband must file within:

1 year from knowledge of the child’s birth (if husband resides in the same city/municipality where the birth occurred or where the family lives, depending on circumstances);
2 years if he resides elsewhere in the Philippines;
3 years if he is abroad.

If the birth was concealed or unknown to him, the period is counted from discovery.

Consequence of missing the deadline: The husband’s right to contest legitimacy is generally lost, and the child’s legitimate status is typically treated as settled.

E. Procedure and evidence (high-level)

Filed in the proper Family Court (R.A. 8369).
The child (a minor) is represented by the mother or a guardian; the court may appoint a guardian ad litem when needed to protect the child’s interests.
Evidence may include proof of non-access, incapacity, medical records, travel records, communications, and DNA testing (see Part 7).

5) Denial of paternity by a putative father (illegitimate context)

When the child is not presumed legitimate (e.g., mother not married at conception/birth, or the child is otherwise illegitimate under the Family Code), disputes are framed as:

Action to establish filiation (filed by the child or the child’s representative); and/or
A defensive denial by the alleged father that he is the parent.

Unlike impugning legitimacy, the law here focuses on proof of filiation, not the protection of a marital presumption.

6) Establishing filiation: how paternity is legally proven

A. Legitimate filiation (Family Code, Art. 172; action rules in Art. 173)

Legitimate filiation may be established by:

Record of birth in the civil register;
Final judgment;
Admission of legitimate filiation in a public document or a private handwritten instrument signed by the parent.

In the absence of the above, legitimate filiation may be established by:

Open and continuous possession of the status of a legitimate child; or
Any other means allowed by the Rules of Court and special laws.

Action to claim legitimacy: Generally treated as strongly protected; the child’s ability to assert legitimate status is not lightly barred.

B. Illegitimate filiation (Family Code, Art. 175, in relation to Art. 172)

Illegitimate filiation is proved by essentially the same methods:

Birth record, final judgment, or a signed acknowledgment (public document or private handwritten instrument), or
Open and continuous possession of status, or other admissible means.

Important time rule (general doctrine reflected in Art. 175): Actions to establish illegitimate filiation are commonly required to be brought during the lifetime of the alleged parent, except in situations where filiation is shown by certain strong documentary proofs (e.g., record of birth or a written admission) that the law treats as sufficient to allow an action within the child’s lifetime. The exact application is fact-sensitive and depends on what proof exists.

C. What “open and continuous possession of status” means (practically)

Courts look for consistent real-world treatment showing the alleged father held the child out as his own, such as:

the child using the father’s surname (where legally supported);
the father providing support, schooling, and medical care;
public acknowledgment to family/community;
the father’s name appearing in school, medical, baptismal, insurance, or employment benefit records;
photos/messages indicating paternal relationship;
cohabitation and the father’s conduct toward the child over time.

No single item is always decisive; the pattern matters.

D. Birth certificates and signatures: careful distinction

A birth certificate can be powerful, but paternity entry issues can arise depending on who supplied the information and whether the father signed or executed a lawful acknowledgment.
If a court determines the civil registry record does not reflect the truth, correction often requires a judicial proceeding (commonly under Rule 108 when filiation is affected).

7) DNA evidence in Philippine paternity/filiation disputes

A. DNA testing is admissible and often persuasive

The Rule on DNA Evidence provides standards for the use of DNA results in court. DNA evidence is typically used to:

exclude a man as the biological father; or
support a probability of paternity.

B. Court-ordered DNA testing

Courts may order DNA testing upon motion and after considering relevance, necessity, and other factors. Practical considerations include:

specimen collection methods;
chain of custody;
accreditation/competence of the testing facility;
whether testing is the least intrusive way to resolve the issue.

C. Refusal or non-cooperation

If a party unjustifiably refuses DNA testing or obstructs it, courts may consider such refusal in evaluating the evidence (the exact legal effect depends on context and judicial appreciation; it is not always automatic “admission,” but it can be damaging).

D. DNA is powerful—but not always the only issue

Even with biological proof, the legal question can still hinge on status rules—especially when legitimacy is presumed by marriage and the strict impugning framework applies.

8) Child support: rights, obligations, and what happens during disputes

A. What “support” includes (Family Code, Art. 194)

Support includes everything indispensable for:

sustenance, dwelling, clothing;
medical attendance;
education and transportation consistent with the family’s financial capacity;
education extends through schooling/training to prepare the child for a profession or vocation.

B. Who must give support (Family Code, Art. 195)

The duty to support arises among:

spouses;
legitimate ascendants/descendants;
parents and their illegitimate children (and vice versa);
legitimate brothers and sisters (in proper cases).

C. When support can be demanded and how far back it reaches

Support is generally demandable from the time the need exists, but recoverable amounts are commonly anchored to judicial or extrajudicial demand (Family Code, Art. 203 and related provisions). Courts routinely award:

current and continuing support, and
arrears from the date of demand (subject to proof and equity).

D. Amount of support (Family Code, Art. 201–202 concept; Art. 206 principle)

Support depends on:

the child’s needs; and
the obligor’s resources/means.

It may be increased or reduced if circumstances change.

9) Remedies for child support while paternity/filiation is contested

A. Support pendente lite (Rules of Court, Rule 61)

A child or custodian may ask the court for support pendente lite—temporary support while the case is pending. This is crucial because filiation cases can take time, and the child’s needs are immediate.

Typical features:

Based on a summary determination of need and capacity;
Not necessarily a final determination of paternity (but the court must have a legal basis to order it against a party);
Subject to adjustment once the main case is resolved.

B. Provisional/urgent support under the Family Code

The Family Code contemplates circumstances where courts can order provisional support in urgent situations (see support provisions, including Art. 208 conceptually).

C. Protection orders in appropriate cases (practical overlap)

Where the facts fall under laws addressing economic abuse or protection of women/children (e.g., certain domestic relationships), courts may include support directives in protective relief. This is not a substitute for filiation adjudication, but can provide immediate enforcement mechanisms when applicable to the relationship and facts.

10) What happens to support if the husband successfully impugns legitimacy?

If a husband successfully impugns legitimacy:

The child’s legitimate filiation to the husband is negated as a matter of law.
The husband’s obligation to support the child as his legitimate child generally ends going forward.
The child may then pursue establishment of filiation against the biological father (if identifiable) and seek support from him.

Transition problem: Courts aim to avoid leaving a child unsupported. This is why interim remedies (like support pendente lite, and support from other legally obliged relatives under Art. 195 when applicable) can matter in real cases.

11) Can the mother or alleged biological father file to “deny” the husband’s paternity?

As a general structural rule under the Family Code:

The husband (and in narrow cases, his heirs) is the proper party to impugn legitimacy within the strict periods.
The law is designed to prevent outsiders from destabilizing a child’s legitimate status.

This does not mean the truth is irrelevant; it means the route to change legal filiation is tightly controlled.

12) Civil registry consequences: birth certificate, surname, and corrections

A. After a court ruling on filiation

If a judgment changes or declares filiation (or removes an erroneous paternity entry), the civil registry record often must be updated. Because filiation affects civil status, corrections typically require a judicial process (commonly Rule 108) rather than purely administrative correction.

B. Use of surname for illegitimate children (R.A. 9255)

An illegitimate child may use the father’s surname if the father acknowledges paternity in a manner recognized by law (e.g., appropriate affidavit or acknowledgment). If paternity is judicially established, the judgment can support the child’s right to use the surname consistent with applicable civil registry procedures.

13) Strategic map: which case fits which situation?

Scenario 1: Mother is married; husband denies paternity

Proper action: Husband files action to impugn legitimacy (Arts. 166–171) within strict deadlines.
Support: Child may seek support pendente lite while the case is pending, depending on circumstances and the court’s basis.

Scenario 2: Mother not married; alleged father denies child

Proper action: Child (through mother/guardian) files action to establish illegitimate filiation (Art. 175), with proof under Art. 172 and admissible evidence (including DNA).
Support: Seek support pendente lite (Rule 61) plus final support and arrears from demand.

Scenario 3: Husband missed the deadline but insists he is not the biological father

Legal consequence: The legitimacy presumption may remain legally controlling; the child’s legitimate status is generally protected once the impugning period lapses.
Support: Obligation as legitimate child typically continues, absent a valid legal change.

Scenario 4: Putative father wants to acknowledge child, but child is presumed legitimate to husband

Barrier: The law prioritizes the legitimate family framework; the putative father’s path is constrained while legitimacy stands. Legal outcomes depend heavily on whether legitimacy can be challenged through the proper action and within periods.

14) Practical proof checklist in filiation and support litigation (non-exhaustive)

Documents and records

Birth certificate and supporting registry documents
Written acknowledgments (public documents; private handwritten instruments signed by the parent)
School records, medical records, insurance/benefit enrollment
Photos, messages, emails showing acknowledgment/relationship
Proof of financial support: remittances, receipts, tuition payments

Witnesses

Relatives, neighbors, teachers, employers who can attest to acknowledgment and status

Scientific

DNA testing with proper chain of custody and credible laboratory processes

For support computation

Pay slips, ITR, bank statements, business records
Proof of child’s needs: tuition, supplies, medical costs, therapy, transportation, food, housing share

15) Key takeaways (doctrinally consistent themes)

If the child is presumed legitimate, the husband must use the specific “impugning legitimacy” action and must meet strict deadlines.
Filiation can be proven through civil registry records, final judgments, written admissions, possession of status, and other admissible evidence—including DNA.
Child support is a continuing obligation based on need and capacity, and courts can order interim support while cases are pending.
Civil registry entries involving filiation usually require judicial correction when changed by court determination.
The system is structured to protect the child’s status and welfare first, while still allowing legal mechanisms to establish biological truth through proper procedures.