I. Executive Summary

A Filipino child’s right to support, inheritance, government-dependent status, and parental protection does not depend on the surname used. What matters is filiation—proof that the person is the child’s father—not whether the child bears his surname. An illegitimate child may (but need not) use the father’s surname if the father acknowledges the child. Using (or not using) the father’s surname does not convert an illegitimate child into legitimate, does not transfer parental authority to the father, and does not erase the child’s rights to support and succession once paternity is legally established.

II. Legal Architecture

1) Family Code (as amended)

Filiation controls rights, not surnames.
Illegitimate child’s default surname: mother’s.
Option to use father’s surname: only if the father acknowledges paternity (e.g., Affidavit of Admission of Paternity, acknowledgment on the birth record, or court/judicial recognition).
Parental authority: for an illegitimate child, the mother exercises sole parental authority by default—even if the child uses the father’s surname—unless a court orders otherwise.
Legitimation: if the parents later marry and the child is eligible for legitimation, the child becomes legitimate with full rights of a legitimate child; surname and filiation are then updated per law.

2) Civil Code (Support & Succession)

Support (child maintenance) is a legal obligation of parents to their children based on filiation.
Succession (inheritance): an illegitimate child is a compulsory heir of the father once filiation is established. The share/legitime is computed by law; surname choice does not affect the right to inherit or the amount of the legitime.

3) Civil Registration & Notarial Practice

Proof of paternity may be shown by: acknowledgment in the birth certificate; Affidavit of Admission/Recognition; public or private writings; DNA evidence; or final court judgment.
Name changes:
- From mother’s to father’s surname (administrative route) if there is valid paternal acknowledgment.
- From father’s back to mother’s or to another surname: typically via judicial change of name on a best interests of the child showing (administrative remedies are limited to clerical errors, day/month/year of birth, and similar).

III. Core Rights & “Benefits” Unaffected by Surname Choice

A. Support (Financial Maintenance)

The child may demand support from the father even if using the mother’s surname, provided paternity is proven.
Support covers sustenance, dwelling, clothing, medical care, education, and transportation—in proportion to the needs of the child and the means of the father.
Interim support can be sought while a paternity case is pending, based on prima facie proof (e.g., DNA probability or credible admissions).

B. Succession (Inheritance)

Once filiation is established, the child is a compulsory heir of the father.
Surname does not enter the formula for the legitime; only filiation and the presence of other heirs do.
If paternity is contested, the child (or legal guardian) may file a petition for compulsory recognition and, where appropriate, seek preservatory relief (e.g., annotation/lis pendens, estate inventory) to protect eventual hereditary rights.

C. Government & Private-Sector Dependent Status

The key is proof of filiation, not the surname on its own. Typical settings:

PhilHealth: listing the child as a dependent of the father requires documents proving paternity (e.g., acknowledged birth certificate, acknowledgment affidavit, or court order).
SSS/GSIS/Pag-IBIG: for beneficiary or dependent status (sickness, death, pension, funeral, loans tied to insurance), agencies require documentary proof of filiation; the child’s surname need not match the father’s.
Company HMO, school benefits, private insurance: plan rules vary, but proof of parental relationship—not the surname—controls.
Tax: current individual income tax rules no longer hinge on personal/dependent exemptions as they once did; in employment settings, documentary proof may matter for benefit eligibility, not for the name per se.

D. Education, Travel, and Identity Documents

School enrollment and records: the child can enroll under the mother’s surname; the father’s consent is not required merely because he is the biological father.
Passport & travel: For an illegitimate child, the mother’s consent generally governs outbound travel; the father’s consent is not required solely by reason of paternity. Surname choice does not change this allocation of authority.
IDs/Passports can be issued under the child’s registered surname (mother’s), with the father indicated in the birth record if acknowledged.

IV. Situations Where Surname Choice Interacts With Rights

1) Child Uses the Mother’s Surname, Father Acknowledges Paternity

Support & benefits: fully demandable on proof of acknowledgment; name mismatch is not a bar.
Inheritance: preserved; file claims with acknowledgment documents.
Parental authority: remains with mother, absent a court order.

2) Father Has Not Acknowledged; Child Uses Mother’s Surname

Support/benefits: may still be pursued through a paternity/filation action (e.g., DNA testing), after which acknowledgment or judicial recognition allows access to benefits and succession rights.
Interim relief: possible (e.g., provisional support), depending on evidentiary showing.

3) Child Uses Father’s Surname (via acknowledgment)

Status: still illegitimate unless legitimated or adopted; surname use does not equal legitimacy.
Authority: mother retains sole parental authority; father may seek custody/visitation only by court order based on best interests of the child.

4) Parents Marry Later (Legitimation)

If the law’s requirements for legitimation are met, the child becomes legitimate by operation of law; parental authority and surname align with legitimacy rules, and all legitimate-child benefits attach thereafter.

V. Evidence & Procedure to Unlock Benefits Without Changing Surname

Collect Primary Proof of Filiation
- Birth certificate with the father named (with his signature/acknowledgment);
- Notarized Affidavit of Admission/Recognition of Paternity;
- Public or private writings of the father admitting filiation;
- DNA testing (high-probability match supports recognition);
- Final court judgment declaring filiation.
Use the Proof Where Needed
- Submit to agencies (PhilHealth/SSS/GSIS/Pag-IBIG), schools, insurers, or courts as required.
- For inheritance, file claims or judicial petitions within the relevant proceedings (e.g., settlement of estate), attaching filiation proof.
If Paternity Is Contested
- File a petition/complaint for recognition of filiation and support.
- Seek provisional support and orders for DNA testing; courts may compel testing and may draw adverse inferences from unjustified refusal to test.
- For estate matters, intervene in the probate/intestate case and seek preservatory measures.

VI. Common Misconceptions—Clarified

Myth: “No father’s surname, no support.” Law: Wrong. Support follows filiation, not surnames. If paternity is proven, support is due.
Myth: “Using the father’s surname makes the child legitimate.” Law: Wrong. Legitimacy is a legal status; surname use does not change it.
Myth: “If the child doesn’t carry my surname, I have no inheritance obligations.” Law: Wrong. Once filiation is established, the child is a compulsory heir regardless of surname.
Myth: “If the child uses my surname, I automatically get custody/decision rights.” Law: Wrong. For an illegitimate child, mother retains sole parental authority unless a court orders otherwise.

VII. Strategic Considerations for Mothers, Fathers, and Guardians

For Mothers/Guardians

Keeping the mother’s surname preserves administrative simplicity in sole-parent authority contexts.
If seeking support/benefits from the father, focus on filiation proof; a change of surname is not required.
For travel/passport, ensure the birth certificate and mother’s IDs are consistent; bring proof of sole parental authority where needed.

For Fathers

If you intend to provide benefits or include the child as a dependent, execute a clear acknowledgment and maintain documentary copies (for agencies/insurers).
If you seek custody/visitation/decision-making, file the appropriate court petition; surname alignment is not a substitute for judicial authority.

For Both Parents

Consider written parenting agreements (custody, visitation, support) submitted to and approved by the court for enforceability.
Handle the child’s sensitive personal information (health, identity documents) under data-privacy and best-interests-of-the-child principles.

VIII. Special Topics

Adoption

Adoption changes filiation (child becomes the legitimate child of the adopter), affecting surname, parental authority, and succession. Post-adoption, the child typically uses the adopter’s surname.

Assisted Reproduction / Acknowledgment Nuances

Documentary preparation should identify the father where applicable; again, surname is secondary to filiation proof for benefits.

Violence Against Women and Children (VAWC) Contexts

Protective orders may address custody/visitation/support and control of the child’s documents regardless of surname; courts focus on safety and best interests.

IX. Practical Checklists

A. To Access Benefits Without Changing the Surname

☐ Gather filiation proof (acknowledgment, writings, DNA, or judgment)
☐ Submit to target agency (PhilHealth/SSS/GSIS/Pag-IBIG/insurer/school)
☐ If rejected for “name mismatch,” escalate with legal citation that filiation controls; provide certified copies
☐ If paternity is disputed, file recognition/support case and seek interim relief

B. To Challenge or Defend Paternity

Petitioner (child/mother): prepare documentary admissions, seek DNA testing, request provisional support
Respondent (alleged father): present counter-evidence; unjustified refusal of DNA may be weighed against you

X. Model Clauses & Drafting Notes (Illustrative)

Affidavit of Admission of Paternity (Key Elements)

Identity of father and child (with birth details)
Clear, voluntary acknowledgment of filiation
Consent (if desired) for the child to use/not use the father’s surname (note: surname choice does not affect legitimacy or parental authority)
Undertaking to support the child per law

Private Support Agreement (Submit for Court Approval)

Monthly support amount; escalation clause
Allocation of education/medical/extraordinary expenses
Visitation/custody terms (if any), always subject to best interests of the child
Data-privacy and dispute-resolution provisions

XI. Key Takeaways

Surname is not the gateway to rights—filiation is.
A child not using the father’s surname can still access support, inheritance, and dependent benefits once paternity is established.
Using the father’s surname does not create legitimacy, does not transfer parental authority to the father, and does not waive the child’s rights.
For practical access to benefits, compile and present proof of filiation to the relevant agency; if contested, pursue recognition and support in court and consider DNA evidence.
Always anchor decisions on the best interests of the child and maintain privacy and dignity in handling the child’s identity.