Child Surname Change to the Father’s Last Name in the Philippines
A comprehensive legal guide
1. Why the child’s surname matters
A surname is more than a label—it is legal evidence of filiation, affects succession rights, determines the correct name in passports, school records, social-security and health-insurance files, and can spare a family years of costly litigation. In the Philippines, the default rules trace back to the Spanish Civil Code of 1889, the Civil Code of 1950, and—since 1988—the Family Code. Later statutes built special, faster tracks to let an illegitimate or mis-registered child carry the father’s last name.
2. Key statutes, rules & case law
| Instrument | What it covers |
|---|---|
| Family Code (1988) Art. 174–176, 177–182 | Surnames of legitimate & illegitimate children; legitimation by subsequent marriage |
| Civil Code (1950) Art. 364–366 | Limits on changing surnames and the duty to use the father’s surname once legitimate |
| Republic Act 9048 (2001) as amended by RA 10172 (2012) | Administrative correction of first names, day/month of birth & sex—not surnames |
| Republic Act 9255 (2004) & its IRR (Admin. Order No. 1-2004 of the Civil Registrar General) | Allows an illegitimate child to use the father’s surname by filing an Affidavit to Use the Surname of the Father (AUSF) |
| Republic Act 9858 (2009) | Legitimation of a child born out of wedlock to parents who could have married at the time of birth but did so only later |
| Republic Act 11222 (2019) | Rectification of simulated births |
| Rules of Court • Rule 103 – Change of Name • Rule 108 – Cancellation or Correction of Entries |
Judicial avenue if administrative remedies are unavailable or opposed |
| SC cases (illustrative) | Garcia v. Registrar, 195 SCRA 228 (1991) – Rule 103 standards Barco v. Court of Appeals, G.R. No. 97132, May 26 1994 – best-interest test for minors Go Jr. v. Ramos, G.R. No. 173241, 25 June 2013 – AUSF cannot be recorded without the father’s express consent |
3. Starting points: whose surname does the child bear at birth?
Legitimate child (parents were married before birth) Family Code Art. 174 – child automatically uses the father’s surname. No further action is required.
Illegitimate child (parents not married at birth) Family Code Art. 176 – default surname is the mother’s. Switching to the father’s last name demands compliance with RA 9255 or—if the parents later marry—legitimation under Art. 177 or RA 9858.
4. Road-map to adopting the father’s surname
| Scenario | Available remedy | Where filed | Core documents |
|---|---|---|---|
| Father acknowledged at birth (his signature already appears on the Certificate of Live Birth) | No change needed—the LCR may annotate “child uses father’s surname” on request | Local Civil Registry (LCR) of place of birth | PSA birth certificate; parents’ IDs |
| Illegitimate child, father willing to recognize now | RA 9255 AUSF (administrative) | Any PSA-accredited LCR (usually the birthplace LCR) | 1. Original PSA birth cert 2. Affidavit to Use the Surname of the Father (AUSF) signed by father + mother (if child < 7) or by child (7–17) 3. IDs of signatories 4. Filing fee (~₱1,000) |
| Parents marry after birth; at the time of birth no legal impediment to marry | Legitimation by subsequent marriage → child becomes “legitimate” | Same LCR; or Philippine Consulate if abroad | 1. Marriage certificate 2. Joint affidavit of legitimation 3. Child’s PSA birth cert |
| Father absent/deceased or paternity opposed | Judicial petition under Rule 103/108 | Regional Trial Court (RTC) of province/city where the child resides | 1. Verified petition 2. Birth cert 3. Proof of paternity (DNA, letters, photos) 4. DOJ-approved publication schedule |
| Child adopted by biological father (rare, used when paternity must be judicially confirmed) | Domestic adoption (RA 8552) or administrative adoption (RA 11642) | DSWD / National Authority for Child Care, then RTC for decree | Petition or simulated-birth rectification papers |
5. The RA 9255 procedure in detail
Who may file?
- Father – always required because he must affirm paternity.
- Mother – signs if child is below 7.
- Child aged 7-17 – must personally sign or give written consent.
- Child 18 + – files alone if competent.
Affidavit to Use the Surname of the Father (AUSF) – contents
- full names of father, mother, and child
- statement that father is the child’s biological parent and that parties agree to use the father’s surname
- declaration that the change is not for an illegal purpose
- undertaking to update all records
Filing & annotation
- Lodge the AUSF, supporting IDs, and PSA Birth Certificate at the LCR where the birth was registered (or the PSA-Central Office if abroad).
- The LCR annotates the birth record; PSA issues a new Certificate of Live Birth on security paper showing the annotation line.
Fees & timeline
- Typical filing fee: ₱1,000–₱1,500 (varies by city/municipality).
- Processing: 2–4 weeks at LCR, then 2–3 months before PSA prints the revised birth certificate.
Effect of RA 9255
- ONLY the surname changes.
- Filiation status remains illegitimate; the father’s recognition does, however, confer the right to support and to a legitime equal to half of a legitimate child’s share (Civil Code Art. 895).
- Inheritance rights apply without need for court action once filiation is proved.
6. Legitimation by subsequent marriage (Art. 177, RA 9858)
| Prerequisites | Parents could have married each other at the time of the child’s birth (no impediment such as prior subsisting marriage); they later marry. |
|---|---|
| How | Parents sign a Joint Affidavit of Legitimation before the LCR that issued the birth certificate. |
| Effect | Child gains legitimate status; automatically bears the father’s surname; entitled to full legitime; parental authority vests jointly. |
| Annotation | Birth record is stamped “LEGITIMATED BY SUBSEQUENT MARRIAGE OF PARENTS ON ____.” |
7. Judicial change of surname (Rule 103) or cancellation/correction of entry (Rule 108)
When needed
- AUSF denied (e.g., signature disputed, paternity contested)
- Father dead or whereabouts unknown and no DNA or written acknowledgment exists
- Competing claims (two men asserting paternity)
Procedure
- File a Verified Petition with the RTC of the province or city where the child resides.
- Pay filing/docket fees (₱3,000–₱5,000).
- Obtain an order for publication once a week for three consecutive weeks in a newspaper of general circulation.
- Conduct trial; present documentary proof (e.g., DNA results), witnesses, and demonstrate that the change “will not prejudice public or private rights and is for proper and reasonable cause.”
- The civil registrar implements the final order by annotating the birth record.
8. Special or complicated situations
| Situation | Practical note |
|---|---|
| Child already using father’s surname in school/records without AUSF | Rectify soon; inconsistencies delay passports and visas. |
| Father abroad | AUSF may be executed before a Philippine Consulate and authenticated (“red-ribbon”/apostille) before filing at LCR. |
| Father deceased | AUSF impossible; use Rule 108 with DNA or a notarized will/acknowledgment written by the father during his lifetime. |
| Foundlings & simulated births | Under RA 11222, rectification or administrative adoption creates an authentic birth record using the adoptive parents’ surname(s). |
| Child ≥ 18 | May file AUSF personally—parental consent no longer required. |
| Dual/foreign citizenship | Philippine surname rules apply in Philippine records; coordinate with the foreign civil registry to avoid divergent surnames on passports. |
9. Practical consequences of taking the father’s surname
- Passport & DFA records – PSA-issued certificate with annotation is mandatory; expect a name-change interview.
- School & bank records – Provide both old and new birth certificates plus the LCR annotation.
- SSS/GSIS/PhilHealth, BIR TIN – file “Change of Name” forms with the annotation.
- Inheritance – recognition (AUSF or legitimation) + PSA record is enough proof for intestate claims; no additional court action is required unless other heirs contest.
10. Sample template: Affidavit to Use the Surname of the Father (AUSF)
Republic of the Philippines City/Municipality of ______________
I, JUAN D. CRUZ, of legal age, Filipino, single/married, and residing at ___________, and MARIA L. SANTOS, of legal age, Filipino, single/married, and residing at ___________, after having been duly sworn, depose and say:
- That we are the biological parents of minor ANA S. SANTOS, born on 15 March 2020 in __________;
- That at birth our child’s Certificate of Live Birth recorded her surname as SANTOS;
- That I, the father, hereby recognize and acknowledge said child as my own and that we desire that she henceforth use my surname CRUZ in accordance with RA 9255;
- That we undertake to cause the amendment of her birth record and all pertinent documents;
- That this affidavit is executed for the purpose of complying with the requirements of RA 9255 and its Implementing Rules.
IN WITNESS WHEREOF, we have hereunto set our hands this ____ day of ________ 20___ at __________, Philippines.
JUAN D. CRUZ MARIA L. SANTOS (Father) (Mother)
SUBSCRIBED AND SWORN to before me …
11. Frequently-Asked Questions
Does RA 9255 make my child legitimate? No. Only legitimation (Art. 177 or RA 9858) or adoption confers legitimate status.
Can the mother alone switch the surname if the father is missing? Not under RA 9255. She must petition the court under Rule 103/108 and prove paternity.
Is DNA testing compulsory? Only when paternity is disputed or the father is unavailable. In uncontested AUSF filings, it is unnecessary.
What if the child is already an adult? He or she may execute the AUSF personally; parental consent is irrelevant.
Can the surname be switched back to the mother’s later? Yes, but only by a Rule 103 judicial petition; RA 9255 is one-way.
12. Takeaways & best practices
- Act early—mismatched surnames complicate visas, scholarships, insurance payouts, and estate settlement.
- Use the simplest path—AUSF is quicker and cheaper than court, but it requires the father’s live participation.
- Keep originals—PSA copies with annotation are needed for life events (marriage, PRC licensure, emigration).
- Consult counsel—rules change (e.g., RA 11642 streamlined adoption in 2022), and local LCR offices vary in practice.
Disclaimer
This article summarizes Philippine statutes and jurisprudence in force as of June 2 2025. It is not legal advice. Consult a Philippine lawyer or the Local Civil Registrar for guidance on your specific facts and for any amendments that may have been enacted after publication.