Use of the Mother’s Surname by an Illegitimate Child in the Philippines
A comprehensive guide for lawyers, registrars, and parents (updated to 2025)
1. Why this matters
A Filipino child’s surname is more than a label; it anchors civil status, inheritance, parental authority, identity documents, and even a sense of belonging. For children born out of wedlock, the default rule is still the mother’s surname, but statutory reforms since 2004 have introduced important options—and pitfalls—when the father is willing to acknowledge paternity. This article stitches together every significant source of law, regulation, and jurisprudence so you can navigate the system with confidence.
2. Statutory Framework at a Glance
| Law / Issuance | Key Date | Core Provision on Surnames |
|---|---|---|
| Civil Code (Art. 364) | 1950 | An illegitimate child generally bears the mother’s surname. |
| Family Code (Art. 176, original) | 1987 | Restates the mother-surname rule; father’s surname not allowed. |
| Republic Act 9255 | Approved 24 Feb 2004 Effectivity 19 Mar 2004 |
Amends Art. 176. Illegitimate child may use the father’s surname if (a) paternity is acknowledged and (b) the RA 9255 procedure is followed. |
| NSO/PSA A.O. 1-2004 (IRR of RA 9255) | 01 Apr 2004 | Lays down the Affidavit to Use the Surname of the Father (AUSF), documentary proofs, age-based consent, and registrar duties. |
| NSO/PSA A.O. 1-2016 | 22 Dec 2016 | Streamlines AUSF filing, introduces stricter ID rules, and clarifies “acknowledgment” evidence. |
| RA 9048 (2001) as amended by RA 10172 (2012) | 2001 / 2012 | Administrative correction of clerical errors and change of first name. Surname changes stay outside its scope unless covered by RA 9255. |
| RA 9858 (Legitimation by Subsequent Valid Marriage) | 11 Dec 2009 | Once legitimated, the child becomes legitimate and automatically bears the father’s surname. |
| RA 11222 (Simulated Birth Rectification Act) | 21 Feb 2019 | When rectified, the child is deemed legitimate and may take the adoptive parents’ surname. |
| Domestic Administrative Adoption Act (RA 11642, 2022) | 21 Jan 2022 | Adopted child may assume the adoptive family’s surname. |
Key take-away: Unless RA 9255 (or legitimation/adoption) is invoked, the child’s default surname is that of the mother, exactly as reflected in her own birth record (usually her maiden surname).
3. The Default Rule: Mother’s Surname
Automatic at birth. The civil registrar must register the Certificate of Live Birth (COLB) within 30 days. If the parents are unmarried, the “Father” box is left blank unless he appears personally to sign the Acknowledgment of Paternity portion.
Which surname of the mother? “Mother’s surname” means her surname on her own birth certificate, not her husband’s (if she later marries someone else). Thus an illegitimate child cannot carry the surname of a step-father just because the mother is now married.
Civil effects even with mother’s surname.
- Support: The father is still obliged to support the child once paternity is proven (Art. 195, Family Code).
- Succession: An illegitimate child is a compulsory heir of both parents (Arts. 887, 895).
- Parental authority: Remains solely with the mother (Art. 176, last paragraph).
- PhilSys ID, passports, school records: All must mirror the COLB.
4. Using the Father’s Surname under RA 9255
Purpose: To give the child the social and psychological benefit of bearing the father’s name without changing the child’s illegitimate status.
4.1 Two indispensable pillars
| Pillar | How proven | Who signs / files |
|---|---|---|
| A. Acknowledgment of Paternity | - Father signs COLB at birth or - Separate Affidavit of Acknowledgment / Admission or - Private handwritten instrument, will, or public document clearly recognizing the child or - Foreign public document (with Philippine authentication) |
The father |
| B. AUSF (Affidavit to Use Father’s Surname) | Prescribed PSA form | If child is 0-6 yrs: mother If 7-17 yrs: child signs with mother’s consent If 18+ yrs: child alone |
Both pillars must be filed with the Local Civil Registrar (LCR) of the child’s place of birth or where the COLB is kept. The LCR forwards an annotated COLB to the PSA for issuance of a new SECPA copy reflecting the father’s surname.
4.2 When the process may fail
- Father refuses or is unavailable. No AUSF = child keeps mother’s surname.
- Father signs AUSF but paternity was never validly acknowledged. Registrar must reject.
- Mother opposes change after initial use of her surname. Supreme Court in Tagolino v. Domingo (G.R. 175886, 05 Jun 2013) held that surname cannot be switched to the father’s without resort to a proper petition under RA 9048/Rule 103 if the requirements of RA 9255 are unmet.
- Multiple fathers claiming paternity. Registrar must await judicial determination.
4.3 Effects
- No change in legitimacy. Child is still “illegitimate” for purposes of Articles 163-176.
- Support and succession rights already exist upon proof of filiation; surname change merely simplifies proof.
- Travel and documents. DFA accepts the new PSA-issued COLB; old passports must be cancelled.
5. Losing or Reverting the Father’s Surname
Once the father’s surname is validly acquired, dropping it is no longer a registrar-level act. The child (or mother, if still a minor) must:
- File a verified petition for change of name under Rule 103 (RTC jurisdiction) or
- Invoke RA 9048 if the registrar classifies the reversion as “correction” rather than “change”—rare in practice.
Grounds commonly cited: abandonment, risk to security, father’s criminal notoriety, or best interest of the child.
6. From Illegitimate to Legitimate: What changes?
| Mechanism | Statute | Who qualifies | Surname outcome |
|---|---|---|---|
| Legitimation by subsequent valid marriage | RA 9858 + Art. 177 | Parents free to marry at child’s conception & do marry later | Child becomes legitimate and must take father’s surname; AUSF is irrelevant. |
| Domestic administrative adoption | RA 11642 | Any child, including illegitimate | Child bears adoptive parents’ surname. |
| RA 11222 rectification of simulated birth | RA 11222 | Child whose birth was simulated before 29 Mar 2019 | Once rectified, child is deemed legitimate; adoptive parents choose surname. |
7. Jurisprudential Highlights
| Case | G.R. No. / Date | Doctrine |
|---|---|---|
| Dumanjug v. Gomos | 204 Phil 806 (1982) | Even before the Family Code, an illegitimate child traditionally bore the mother’s surname unless legitimated. |
| Silitonga v. Republic | G.R. 211829, 10 Jan 2017 | RA 9255 does not confer automatic right to the father to impose his surname; strict compliance required. |
| Tagolino v. Domingo | G.R. 175886, 05 Jun 2013 | Once registered with the mother’s surname, switching to father’s surname needs RA 9255 compliance or a proper court petition; a barangay official cannot order it. |
| Grande v. Antonio | G.R. 206248, 18 Feb 2014 | Illegitimate children, whether they use father’s or mother’s surname, are still compulsory heirs entitled to their legitime. |
(Older cases under the Civil Code, e.g., Alfonso v. Juanson, remain persuasive only insofar as they align with the Family Code and RA 9255.)
8. Administrative Nuts-and-Bolts
| Item | Where / what | Validity period / fee (2025 rate) |
|---|---|---|
| AUSF form | Download from PSA or obtain from LCR | Notarization + ₱ 230 filing fee |
| Supporting IDs | PSA requires at least 1 gov’t-issued ID from each signatory; child’s school ID acceptable. | Must be unexpired. |
| Processing time | LCR: 3-5 working days to annotate COLB → PSA: 2-3 months for SECPA copy. | Rush service (₱ 200) at PSA Serbilis centers. |
| Authentication (Apostille) | DFA | ₱ 100 (regular, 3-5 days) |
9. Frequently Asked Questions
May the mother choose the father’s surname even if the father is silent? No. RA 9255 demands the father’s express acknowledgment.
Can the child use a hyphenated surname (Father-Mother)? The statute does not provide for double surnames; registrars usually reject the hyphenated form absent a court order.
What if the father later denies paternity after an AUSF was filed? The registrar cannot unilaterally cancel the entry; father must sue for action to impugn acknowledgment under Art. 170.
Does the father gain parental authority once the child bears his surname? No. Parental authority remains with the mother unless the child is subsequently legitimated or adopted.
Is DNA testing required? Not for AUSF. It becomes relevant only in court proceedings to prove or disprove paternity.
10. Practical Checklist for Parents & Counsel
- Decide early. The simplest moment to use the father’s surname is at the birth registration when both parents are present.
- Keep originals. Retain notarized AUSF, IDs, and acknowledgment documents; PSA may request resubmission.
- Educate the child. Children aged 7-17 must co-sign; refusal is respected.
- Plan for downstream records. Coordinate with schools, PhilHealth, and banks to update the child’s records once the new COLB arrives.
- Seek legal advice for contested cases. Court petitions are unavoidable if the registrar disallows the change or if another party objects.
11. Policy Trends (2025 and beyond)
- Digital Civil Registry System (DCRS). PSA is piloting e-COLBs with QR-code verification; surname annotations are expected to migrate to real-time digital updates.
- Gender-neutral language. Bills in the 20th Congress propose replacing “illegitimate” with “non-marital” child, but they retain the mother-surname default pending broader overhaul.
- Stricter identity screening. In response to identity theft, PSA Circular 2024-05 now mandates biometric capture for fathers executing AUSFs.
12. Conclusion
Under Philippine law, an illegitimate child’s starting point is the mother’s surname—a rule rooted in protection of maternal authority and administrative convenience. RA 9255 carved out a carefully-gated door to the father’s surname, but only when acknowledgment and the AUSF walk hand-in-hand. Beyond that, true transformation of the child’s civil status—and therefore surname—lies in legitimation or adoption statutes.
For parents, precision in paperwork today prevents heartaches tomorrow. For practitioners, mastery of both the letter and the administrative mechanics of RA 9255 remains indispensable, because the “simple” question of which surname a child may carry will always be entwined with deeper questions of filiation, parental rights, and social identity.
(This article is informational and does not constitute legal advice. For specific cases, consult a Philippine lawyer or the local civil registrar.)