I. Overview

Republic Act No. 9255 (RA 9255) allows an illegitimate child to use the surname of the father—but only under specific conditions and through defined administrative procedures. RA 9255 amended Article 176 of the Family Code, which generally provides that illegitimate children use the mother’s surname and remain under the mother’s parental authority.

RA 9255 does not automatically make a child legitimate, does not automatically confer paternal parental authority, and does not by itself guarantee inheritance rights beyond what the law on illegitimate filiation already provides. Its central feature is surname use, anchored on proof of paternal recognition.

II. Key Concepts You Must Understand

1) Who is an “illegitimate child”?

A child is illegitimate if the parents were not legally married to each other at the time of the child’s birth, and the child is not otherwise legitimated by subsequent marriage (and other legal requisites).

2) “Use” of father’s surname is different from “legitimation”

RA 9255: changes the surname used by an illegitimate child, once the father recognizes the child in the manner required.
Legitimation (Family Code): may occur when parents later marry and the child was not disqualified from legitimation; this changes the child’s status to legitimate (with broader effects).

3) “Recognition” is the cornerstone

RA 9255 is not a mere name-change preference. The child may use the father’s surname only if there is valid proof that the father recognized the child.

III. Who May Apply Under RA 9255

A. The child (through proper representative)

A minor child applies through the mother or a legally authorized representative/guardian, depending on the situation.
An adult child (generally 18 or older) may apply on their own behalf.

B. The mother (common scenario)

The mother often files the request to use the father’s surname if the father’s recognition exists in the required form (explained below), or if the father executes the necessary document.

C. The father (in appropriate cases)

The father may facilitate the process by executing the required affidavit/document and coordinating with the civil registry procedures (but the mother/child may still need to participate depending on the child’s age and registry situation).

IV. Eligibility Requirements (Substantive)

To be eligible to apply RA 9255, the following must generally be true:

1) The child is illegitimate

If the child is legitimate, RA 9255 is not the route; legitimate children already carry the father’s surname as a rule.

2) The father has recognized the child

Recognition must be shown through legally accepted documents, commonly through:

a) The father’s signature on the Certificate of Live Birth (COLB) If the father signed in a manner that constitutes recognition (not merely as “informant” without acknowledging paternity), this can be the basis.

b) An Affidavit of Acknowledgment / Affidavit of Admission of Paternity A sworn instrument where the father explicitly acknowledges paternity.

c) A private handwritten instrument signed by the father (where legally accepted) In some contexts, a private document acknowledging the child can support recognition, but civil registrars typically require compliance with the implementing rules and may still prefer/require the specific affidavit format.

d) Other documents that establish recognition under civil registry rules Depending on the facts, civil registrars may accept certain records, but the most common is the affidavit of paternity plus the required surname-use affidavit.

3) Compliance with the administrative process

Even if recognition exists, the surname change is not “self-executing.” The civil registry must annotate/record the change following prescribed procedure.

V. The Core Document: Affidavit to Use the Surname of the Father (AUSF)

A central feature of RA 9255 practice is the Affidavit to Use the Surname of the Father (AUSF).

What the AUSF does

It expresses the request/authority for the illegitimate child to use the father’s surname, anchored on the father’s recognition.

Who signs the AUSF

Common patterns:

If the child is a minor: the mother typically executes the AUSF (with required supporting documents showing paternal recognition).
If the child is of age: the child may execute the AUSF personally.

Important: The AUSF is not, by itself, the “proof of paternity.” It is the instrument for the surname-use request, while recognition/paternity must be established through the father’s acknowledgment documents.

VI. Typical Scenarios and Whether RA 9255 Applies

Scenario 1: Father’s name is on the birth certificate and he signed acknowledging paternity

Generally eligible, subject to proper documentation and civil registry review.

Scenario 2: Father’s name is on the birth certificate but he did not sign to acknowledge paternity

Eligibility depends on whether there is another valid proof of recognition (e.g., affidavit of paternity). If none, the process usually cannot proceed administratively.

Scenario 3: Father is not named on the birth certificate, but he is willing to acknowledge paternity now

Generally eligible once the father executes the required affidavit(s) and the civil registry process is followed (often involving supplemental registration/annotation).

Scenario 4: Father is not named and refuses to acknowledge

RA 9255 cannot be used to unilaterally compel surname use without paternal recognition. A judicial action to establish paternity may be necessary if the goal is to compel recognition.

Scenario 5: Father is deceased

It may still be possible if there exists a legally acceptable written acknowledgment executed during his lifetime (or other legally recognized proof of filiation that civil registry rules allow). If none, the route may become judicial.

Scenario 6: Father is foreign

RA 9255 may still apply in Philippine civil registry context if the child’s birth is registered in the Philippines and the required recognition documents are provided in acceptable form (often with consularization/apostille and proper authentication where needed).

VII. Where and How to File (Administrative Side)

A. Where to file

Typically with the Local Civil Registry Office (LCRO) where the birth was registered. In some cases, filing may be allowed where the applicant resides, but annotation/endorsement still ties back to the registry of birth.

B. What happens to the record

The civil registrar usually:

Evaluates the documents
Records the AUSF and recognition instruments
Causes annotation on the birth record that the child shall use the father’s surname pursuant to RA 9255
Issues updated/annotated civil registry documents

C. What the applicant generally submits

Exact checklists vary per LCRO practice, but commonly include:

Certified true copy of birth certificate / COLB
AUSF (notarized)
Proof of father’s acknowledgment (affidavit of paternity / acknowledgment, or birth certificate signature as acknowledgment)
Valid IDs of signatories
If executed abroad: authenticated/apostilled documents + translations if needed
Other supporting documents as required by LCRO

VIII. Effects of Using the Father’s Surname Under RA 9255

1) The child remains illegitimate (unless legitimated/adopted, etc.)

RA 9255 does not change civil status by itself.

2) Parental authority generally remains with the mother

Under Article 176, illegitimate children are under the parental authority of the mother. Using the father’s surname does not automatically transfer or share parental authority.

3) Support and obligations

A father who acknowledges paternity may be pursued for support consistent with laws on filiation and support. Surname use can be relevant evidence contextually, but support rights flow from filiation, not from the surname alone.

4) Inheritance rights

Illegitimate children have inheritance rights under the Civil Code/Family Code framework on succession, but generally at a different share compared to legitimate children. RA 9255 does not “upgrade” inheritance status; filiation and the rules on succession govern.

5) Identity documents (school records, passports, IDs)

Once properly annotated/recorded, the child may use the father’s surname in official transactions, but agencies often require:

PSA-issued birth certificate showing annotation, or
Supporting civil registry documents reflecting the RA 9255 action

IX. Limits, Risks, and Common Misunderstandings

Misunderstanding 1: “If the father’s surname is used, the child is legitimate.”

False. Legitimacy is determined by law (marriage/legitimation/adoption), not by surname.

Misunderstanding 2: “The mother can apply even if the father never acknowledged.”

RA 9255 is anchored on paternal recognition. If the father does not acknowledge, administrative RA 9255 is typically unavailable; the remedy may be judicial establishment of filiation.

Misunderstanding 3: “Using the father’s surname gives the father custody.”

Not automatically. Parental authority rules remain, absent a court order or applicable special circumstances.

Misunderstanding 4: “A surname change fixes everything for school/records instantly.”

Institutions may require time and specific documents (annotated PSA birth certificate). Some will request additional affidavits for record corrections.

X. Special Situations

A. If the parents later marry

The child may become legitimated if legal requirements are met and the child is not disqualified. In that case, the child’s records may need updating under legitimation rules, which can have broader effects than RA 9255.

B. If there is a dispute on paternity

If paternity is disputed, civil registrars may not act administratively without clear documentary compliance. Courts may be needed to resolve paternity.

C. If the child was adopted

Adoption produces its own naming consequences depending on the type of adoption and applicable orders; RA 9255 may become irrelevant or secondary to adoption decrees.

D. If the birth was late-registered or has errors

Late registration or clerical issues may require additional steps (and sometimes separate correction procedures) before or alongside RA 9255 annotation.

XI. Practical Eligibility Checklist

You are generally eligible to apply under RA 9255 if you can answer YES to the following:

Is the child illegitimate?
Is there valid proof the father acknowledged/recognized the child?
- Father signed the birth record acknowledging paternity; or
- Father executed an affidavit of paternity/acknowledgment; or
- There is another recognized written acknowledgment acceptable under civil registry rules.
Can you execute/submit the AUSF (by the mother for a minor, or by the child if of age), with proper IDs and notarization?
Are you filing with the proper civil registry office (and prepared for annotation requirements)?

If any answer is NO, the case may require different remedies (additional documents, legitimation procedures, or judicial action to establish filiation).

XII. Frequently Asked Questions

1) Can the child use the father’s surname even if the father is not listed on the birth certificate?

Potentially yes, if the father provides legally acceptable acknowledgment and the civil registry process is followed to reflect it.

2) Can the mother alone decide to change the child’s surname to the father’s?

Not purely by choice. The law requires father’s recognition.

3) Does RA 9255 apply to all ages?

It can apply to minors and adults, but the signing/consent mechanics differ (mother for minors; adult child may act personally).

4) If the father acknowledges, is he automatically entitled to visitation or custody?

Not automatically. Custody/visitation can be subject to agreements and court determinations, and parental authority rules still matter.

5) Can the child later revert to the mother’s surname?

This is not treated as a casual preference change; it may require a separate legal basis/process (often judicial), depending on circumstances and agency requirements.

XIII. Conclusion

RA 9255 provides a lawful path for an illegitimate child to use the father’s surname, but eligibility is not based on preference—it is based on documented paternal recognition and proper civil registry procedure, typically through an Affidavit to Use the Surname of the Father (AUSF) supported by proof of acknowledgment.

If the father does not acknowledge the child, or if documentation is insufficient, RA 9255 usually cannot be completed administratively and the remedy may shift to judicial establishment of filiation or other applicable family law processes.

This article is for general legal information in the Philippine context and is not a substitute for advice on a specific case.