Requirement for a Father’s Signature in Surname Changes (Philippine Law)

This article explains when a father’s signature is legally required—or not—when changing a child’s surname in the Philippines. It draws from the Family Code, the Civil Code and Rules of Court (Rules 103 & 108), and special laws like RA 9048/10172 and RA 9255. It is general information, not legal advice.

The Legal Landscape (Quick Map)

Default rule for surnames
- Legitimate children (parents married to each other at conception or birth): child uses the father’s surname by default.
- Illegitimate children (parents not married to each other): child uses the mother’s surname by default; may use the father’s surname only if paternity is acknowledged under RA 9255.
Two very different pathways to any “surname change”
1. Administrative (Local Civil Registrar/PSA) Limited to: change of first name/nickname and clerical/typographical errors (RA 9048 as amended by RA 10172). Surname changes are generally not allowed administratively, except: an illegitimate child’s switch to the father’s surname under RA 9255 when the father formally acknowledges paternity.
2. Judicial (Court petition) For all other surname changes (e.g., legitimate child dropping the father’s surname; reverting from father’s to mother’s surname outside RA 9255 process; hyphenations; contested cases; no documentary acknowledgment). Proceed under Rule 103 (Change of Name) and/or Rule 108 (Civil Registry Corrections).

When is the Father’s Signature Required?

A. Illegitimate child adopting the father’s surname (RA 9255)

Yes—father’s signature (acknowledgment of paternity) is essential.

To use the father’s surname without going to court, the law requires proof that the father has acknowledged the child through any of the following:

The father signed the Certificate of Live Birth acknowledging paternity; or
The father executed an Affidavit of Admission/Acknowledgment of Paternity (AAP/AAL); or
The father authored a Private Handwritten Instrument (PHI) unequivocally admitting paternity.

Why the signature matters: RA 9255 is an exception that allows a change in surname usage for illegitimate children administratively. The trigger is the father’s acknowledgment. Without it, the Local Civil Registrar (LCR) cannot lawfully process the switch to the father’s surname.

Practical notes

If the child is a minor, the application is filed by the mother or guardian via an Affidavit to Use the Surname of the Father (AUSF). The child’s written consent is usually required once the child reaches the age of discernment (commonly treated as 7–17).
If the child is 18 or older, the child can file the AUSF personally. The father’s earlier acknowledgment must still exist in acceptable form.
If the father is abroad, his AAP/AAL must be consularized or apostilled, as applicable.
If the father is deceased, RA 9255 can still be used if an earlier, valid acknowledgment exists (e.g., his signature appears on the birth certificate or a prior AAP/PHI). If no prior acknowledgment, administrative route is closed.

When is the Father’s Signature Not Required?

B. Legitimate child seeking a different surname (e.g., to the mother’s surname)

This requires a court petition (Rule 103/108).
The father’s consent/signature is not a statutory requirement to file or grant the petition; however, he is a necessary party and will be notified/served. Courts decide based on substantial and reasonable cause and the best interests of the child.
Examples argued in court include: the surname causes confusion or stigma; long, continuous use of another surname; abandonment or circumstances showing the change serves the child’s welfare. Outcomes are case-specific.

C. Adult (of any filiation) petitioning to change their own surname

An adult may file a Rule 103 petition.
No parent’s signature is required. The key is proving proper and reasonable cause, such as consistent prior use, difficulty/embarrassment, or other compelling welfare grounds.

D. Clerical/typographical corrections (RA 9048/10172)

If the issue is not a change of surname but a clerical error (misspelling, transposition) in the father’s name or similar, it can be fixed administratively.
Depending on the filer (owner of the record, parent, guardian), the father’s signature is not inherently required—unless the LCR needs it to validate a particular correction (e.g., to confirm the correct spelling of the father’s name). This does not authorize switching to or from the father’s surname.

E. Adoption and legitimation

Adoption: Upon a final decree of adoption, the child assumes the adoptive parent’s surname. The biological father’s signature is irrelevant; the court decree controls.
Legitimation by subsequent marriage (for children conceived and born before the parents’ marriage, subject to legal requirements): the child becomes legitimate and assumes the father’s surname through legitimation proceedings/annotation. This is rooted in the marriage and affidavits/annotations, not an independent “surname change” needing a separate new father’s signature at the LCR.

What if the Father Refuses or is Unavailable?

Illegitimate child wanting the father’s surname, but no acknowledgment?
- Administrative path is closed.
- The remedy is a court action to (a) establish filiation (paternity) and (b) seek a change of surname. Evidence may include DNA testing, credible documents, and testimony. Courts weigh best interests of the child and public policy.
Illegitimate child already acknowledged but the father later objects:
- A valid acknowledgment typically cannot be unilaterally withdrawn by the father. The child’s right to use the father’s surname (once validly acquired under RA 9255) generally persists, though particular disputes may still end up in court for resolution of which surname will appear in the civil registry following contested circumstances.
Emergency documents (passport, school records) vs. PSA record
- Government IDs and school records generally follow the PSA birth record. If the PSA still shows the mother’s surname, agencies will usually require you to fix the PSA first (via RA 9255 or a court order) before they reflect the father’s surname.

Typical Paperwork & Who Signs What

RA 9255 (Illegitimate child → father’s surname)

Core prerequisite: a documented acknowledgment of paternity by the father (signature on birth certificate, AAP/AAL, or PHI he wrote).
AUSF (Affidavit to Use the Surname of the Father):
- Filed by the mother/guardian (for minors) or the child (if 18+).
- Father does not sign the AUSF itself; his role is the separate acknowledgment proving paternity.
Supporting documents often include: PSA birth certificate, valid IDs, acknowledgment document, child’s written consent (if minor of sufficient age), and, if executed abroad, apostille/consularization.

Court Petitions (Rules 103 & 108)

Petitioner: the person whose name will change (a minor acts through a parent/guardian).
Respondents/Notice: the civil registrar and interested parties (including the father).
Father’s signature is not a precondition to file; due process notice is.

Key Distinctions That Avoid Headaches

“Using the father’s surname” under RA 9255 ≠ generic “change of surname.” It’s a narrow administrative doorway open only to illegitimate children if and only if the father already acknowledged paternity in the proper documentary forms.
No acknowledgment = no RA 9255 route. The option becomes a court case—not an LCR desk affair.
Clerical vs. Substantive. Fixing a misspelling of the father’s name is not the same as switching surnames. RA 9048/10172 gets you the former, not the latter (except RA 9255’s special case).
Adoption and legitimation are sui generis. The surname flows from the decree (adoption) or legitimation event, not from a new paternal signature requirement.

Simple Decision Guide

Are the parents married to each other?
- Yes (legitimate child): Default is father’s surname. To change it → court. Father’s signature not required (but he’s notified).
- No (illegitimate child): Default is mother’s surname. Go to (2).
Did the father acknowledge paternity via signed birth record/AAP/PHI?
- Yes: You may administratively adopt the father’s surname under RA 9255.
  - Who signs now? The mother/guardian (AUSF for minors) or the child (if 18+). The father’s prior acknowledgment document is the key.
- No: Administrative route unavailable. Consider a court petition to establish filiation and seek surname change. Father’s signature not required to file, but his participation/notice will be part of the case.

Frequently Asked Practical Questions

Can a mother alone switch an illegitimate child to the father’s surname at the LCR? Only if there is existing documentary acknowledgment by the father (his signature on birth record/AAP/PHI). Otherwise, no.
Father won’t sign any acknowledgment—what now? Court petition to establish paternity and request the surname change.
Father already signed the birth certificate years ago. Do we still need him to sign something new? Generally no. The existing acknowledgment enables the RA 9255 process; the AUSF comes from the mother/guardian or the adult child.
Can the father later force the child to stop using his surname? As a rule, a valid acknowledgment cannot be unilaterally withdrawn. Disputes are resolved by courts, focusing on the child’s best interests.
What about middle names for illegitimate children? Middle-name rules are policy-driven and have evolved administratively. In practice, when an illegitimate child adopts the father’s surname under RA 9255, many LCR/PSA implementations allow the mother’s surname as the middle name; without RA 9255, an illegitimate child typically has no middle name. Specific local practice can vary—check with your LCR.

Takeaways

The only common situation where a father’s signature is indispensable is the acknowledgment of paternity to unlock RA 9255’s administrative switch for illegitimate children.
Most other surname changes run through the courts, where the father’s consent/signature is not a prerequisite, though he is notified and may be heard.
When in doubt, verify with your Local Civil Registrar (for administrative options) or consult counsel (for judicial routes), especially for cases involving foreign documents, deceased or absent fathers, or contested situations.

Helpful (non-exhaustive) document checklist

RA 9255 route (illegitimate → father’s surname)
- Father’s acknowledgment (signed birth certificate or AAP/AAL or PHI)
- AUSF (mother/guardian for minors; child if 18+)
- PSA birth certificate (current)
- Valid IDs (applicant and, if required, the father)
- Child’s written consent (if minor of sufficient age)
- Apostille/consularization for foreign-executed docs
Court route (Rule 103/108)
- Verified petition with grounds and supporting evidence
- Copies of civil registry records (birth/marriage, etc.)
- IDs, proofs of continuous usage (if relevant), and service on concerned parties (including the civil registrar and the father)

If you’d like, tell me your exact scenario (child’s status, existing documents, where you’ll file), and I can map the precise steps and paperwork you’ll likely need.