Changing the Surname of an Illegitimate Child: RA 9255 and Court Options (Philippine Context)

Under Article 176 of the Family Code, an illegitimate child (a child born outside a valid marriage, subject to statutory exceptions) traditionally:

Uses the mother’s surname, and
Is under the exclusive parental authority of the mother.

This default matters because changing the surname of an illegitimate child is not simply a “name preference” issue; it’s tied to filiation (legal parentage) and to what the law allows civil registrars to record.

2) What RA 9255 changed

Republic Act No. 9255 amended Article 176. Its core change:

An illegitimate child may use the surname of the father if the child’s filiation with the father has been expressly recognized in the manner allowed by law.

Key points:

The child’s use of the father’s surname is permissive (“may”), not automatic.
Using the father’s surname does not legitimize the child. Legitimacy is a different legal status and changes only through specific legal mechanisms (e.g., legitimation by subsequent marriage, adoption, etc.).
RA 9255 is implemented through administrative procedures with the Local Civil Registrar (LCR) and annotation with the PSA.

3) The legal requirement: recognition of paternity (filiation)

RA 9255 operates only when the father has recognized the child. Recognition is proven through any of the legally accepted modes for establishing illegitimate filiation, such as:

Record of birth (birth certificate) showing the father’s acknowledgment/recognition, typically evidenced by the father’s signature and details recorded in a manner consistent with acknowledgment; and/or
Admission of filiation in a public document (e.g., notarized acknowledgment); and/or
Admission in a private handwritten instrument signed by the father (a very specific type of document—handwritten and signed by him, not merely typed and signed).

Practical takeaway: You can’t use RA 9255 to shift the surname to the father’s surname if there is no valid proof of the father’s recognition.

4) The administrative mechanism: the Affidavit to Use the Surname of the Father (AUSF)

The usual route under RA 9255 is administrative (no court case) through the Affidavit to Use the Surname of the Father (AUSF) filed with the Local Civil Registrar where the birth is registered.

Who signs the AUSF

Commonly:

The mother signs if the child is a minor;
The child may sign if the child is of age (commonly treated as 18 and above);
If the mother is unavailable due to death/incapacity, practice often involves a guardian or legally authorized representative, but registrars vary—expect stricter documentation.

When AUSF is used

Two common situations:

A) Child not yet registered (late or current registration):

The birth is registered with documents showing the father’s recognition; and
AUSF is filed so the child can be registered using the father’s surname from the start.

B) Child already registered under the mother’s surname:

AUSF is filed with the LCR to annotate the record so the child can thereafter use the father’s surname;
The PSA record is updated through annotation (not a “new” birth certificate, but an annotated one, depending on PSA issuance format/policy at the time of release).

What AUSF does—and does not—do

AUSF does:

Authorize recording/annotation that the illegitimate child will use the father’s surname (because the father has recognized the child).

AUSF does not:

Make the child legitimate;
Automatically grant parental authority to the father;
Substitute for proof of filiation if recognition is missing or defective.

5) Typical document set (what civil registrars commonly look for)

Requirements vary slightly by LCR, but commonly include:

Duly accomplished AUSF;
Birth certificate (LCR copy and/or PSA copy, depending on stage);
Proof of father’s recognition (often one or more of the following):
- Birth certificate entries consistent with acknowledgment and/or father’s signature where required by the registrar’s rules, or
- Notarized acknowledgment/public document, or
- Private handwritten instrument signed by the father;
Valid IDs of the affiant(s);
Supporting documents if there are special circumstances (death certificate if father is deceased; guardianship papers if mother is unavailable; etc.).

Because LCR practices differ, “missing recognition proof” is one of the most common reasons filings get rejected.

6) Common scenarios and what route applies

Scenario 1: The father recognizes the child and everyone agrees

Best route: RA 9255 (AUSF) administrative annotation

Fastest, least expensive, least adversarial.

Scenario 2: The father did not recognize the child, but the mother wants the father’s surname anyway

RA 9255 alone will not work. The mother must first establish filiation. That typically means a court action to establish paternity/compulsory recognition, or at least obtaining a legally adequate recognition instrument from the father.

Court route: File a case to prove filiation (paternity). Once paternity is established, the civil registry entry can be corrected/annotated.

Scenario 3: The father denies paternity and refuses to sign anything

This is a court case. You’re not just changing a name—you’re trying to establish a legal relationship.

Possible tools in court:

Evidence of written admissions, messages, support, conduct, “open and continuous possession of status,” etc.;
DNA testing may be sought depending on the case posture and the court’s orders.

Once the court declares paternity/filiation, the surname issue becomes implementable through court-directed correction/annotation of the civil registry record.

Scenario 4: The child is already an adult and wants to use the father’s surname

If there is prior valid recognition, the adult child may typically proceed with AUSF (signed by the adult child). If recognition is missing/disputed, it becomes a filiation case.

Scenario 5: The parents later marry (legitimation)

If the child was eligible for legitimation by subsequent marriage (and no legal impediment existed at the time of conception/birth other than the lack of marriage), legitimation:

Changes the child’s status to legitimate, and
The child generally uses the father’s surname as a legitimate child.

This route is conceptually different from RA 9255. Legitimation is about status, not just surname.

Scenario 6: The child wants to revert back to the mother’s surname after using the father’s surname

This is where people often get surprised:

RA 9255 is designed to allow use of the father’s surname upon recognition; it is not always treated as a “toggle” you can flip repeatedly through simple administrative filings.
Reversion attempts often run into civil registry rules that treat subsequent name changes as needing a judicial basis (because it’s no longer a straightforward annotation under RA 9255).

In many cases, a court petition becomes the practical route, especially if the record has long been used in school, passports, IDs, and other public records.

7) The “court options” in detail: which petition fits which problem

In the Philippines, court pathways depend on what exactly needs to be changed and why.

A) Case to establish filiation (paternity) / compulsory recognition

Use when: the real dispute is whether the man is legally the father, or when recognition is absent and cannot be obtained voluntarily.

Result: a judgment establishing filiation, which then supports annotation/correction of the civil registry and the surname to be used.

B) Rule 108 petition (cancellation or correction of entries in the civil registry)

Use when: you need a court-ordered correction/annotation of a civil registry entry and the change is substantial (not merely a typographical error). Surname changes tied to filiation disputes typically fall into the “substantial” side.

Rule 108 is commonly used when:

The civil registry entry must be corrected based on a legal fact (e.g., paternity established by judgment);
The correction affects civil status/filiation or other substantial entries.

Because these cases can be adversarial, proper notice and participation of interested parties is important.

C) Rule 103 petition (change of name)

Use when: the issue is framed as a change of name for compelling reasons, and not merely correction of an entry. Courts are cautious about Rule 103 when the underlying aim is to alter records tied to filiation or civil status; depending on the facts, Rule 108 may be more appropriate, or both get discussed in litigation strategy.

D) Administrative correction laws (RA 9048 / RA 10172) — limited use

These laws allow administrative correction of certain civil registry entries (clerical/typographical errors; and, for RA 10172, certain day/month errors and sex entry under specific conditions). They are not a general tool to switch an illegitimate child from the mother’s surname to the father’s surname absent RA 9255 recognition or a court order, because that is usually viewed as substantial, not clerical.

8) Effects on custody, parental authority, support, and inheritance

People often assume “using the father’s surname” automatically changes everything. It doesn’t.

Parental authority / custody

As a general rule under Article 176, the mother retains exclusive parental authority over an illegitimate child. The father’s recognition and the child’s use of surname do not automatically transfer custody or parental authority.

Support

A father who is legally established as the parent has an obligation to provide support. Recognition/filiation is what matters—not the surname alone.

Inheritance (successional rights)

Illegitimate children have inheritance rights from the father under Philippine law, but generally in a different measure than legitimate children. Again, filiation is key.

9) Practical pitfalls (where applications commonly fail)

No valid proof of recognition by the father (AUSF cannot substitute for recognition).
Attempting to treat a surname change as a “clerical correction.”
Inconsistent documents: school records, baptismal, hospital records, IDs using different names without a clear legal basis.
Late registration complications (registrars often require more supporting proof).
Expecting the father’s surname to confer legitimacy or custody rights.

10) A clear decision tree (quick guide)

Is the father’s recognition legally documented?
- Yes: proceed with RA 9255 (AUSF) administrative annotation/registration.
- No: go to court to establish filiation (paternity), then implement record changes via court-directed correction/annotation.
Is the change “substantial” (affecting filiation/civil status), or just a typo?
- Substantial: usually Rule 108 (and/or filiation case).
- Clerical typo: possibly RA 9048/10172 (case-specific).
Are the parents now married and the child eligible for legitimation?
- Consider legitimation processes (status change), not only RA 9255.

11) Bottom line principles

RA 9255 is the administrative path to let an illegitimate child use the father’s surname when the father has legally recognized the child.
No recognition, no RA 9255 surname shift—the dispute becomes one of filiation, which is typically resolved in court.
Many “surname change” problems are really “civil registry + filiation” problems; that is why Rule 108 and paternity/filiation actions are central court tools.
Surname use ≠ legitimacy, and surname use ≠ custody transfer.