Change of Surname for an Illegitimate Child in the Philippines

Process, cost, timeline, and everything you need to know (Philippine context)

This is a practical guide based on Philippine law and standard civil-registry practice. Rules can change and local civil registry offices (LCROs) may add requirements, so treat the figures below as typical—not universal—and check with your LCRO.

The big picture

Default rule: An illegitimate child (born outside a valid marriage) uses the mother’s surname.
Exception (RA 9255): The child may use the father’s surname if the father expressly recognizes the child (e.g., by signing the birth record or an admission of paternity) and the required affidavit(s) are filed.
This does not change civil status. Using the father’s surname does not make the child legitimate and does not transfer parental authority; the mother retains parental authority unless a court says otherwise.
Other pathways exist: Legitimation after the parents later marry, adoption (now administrative via the NACC), or a court petition to change a surname for compelling reasons.

Legal bases (at a glance)

Family Code of the Philippines (EO 209), Art. 176 as amended by RA 9255 (2004) – allows an illegitimate child to use the father’s surname upon proof of filiation/recognition.
RA 9255 IRR (Civil Registrar General A.O. 1, s. 2004) – forms and workflow (e.g., AUSF).
RA 9048 (2001), as amended by RA 10172 (2012) – clerical corrections and change of first name/day & month of birth/sex due to clerical error; not a general route to change surnames.
Rule 103, Rules of Court – judicial change of name/surname for proper and reasonable cause when no administrative route fits.
RA 9858 (2009) – legitimation even if parents were below marrying age at conception; effects retroact to birth.
RA 11642 (2022) – Domestic Administrative Adoption via the National Authority for Child Care (NACC); adoption changes the child’s status and surname to the adopter’s.

All practical routes to change (or choose) a surname

1) Use the father’s surname at birth (fastest)

When: Father is present to acknowledge at registration. How: Father signs the Certificate of Live Birth (COLB) and the Affidavit of Admission of Paternity (AAP); the child is registered immediately under the father’s surname. Who signs: Father (AAP); the informant on the COLB (often the mother or hospital). Cost & timeline (typical): Minimal beyond normal birth registration fees; completion is same day at the LCRO. PSA copies with the father’s surname are available once the record is transmitted (often 2–6 weeks to appear in PSA systems).

2) Switch to the father’s surname after registration (RA 9255 Annotation)

When: Child was already registered under the mother’s surname, but father later recognizes the child. Key documents:

AAP – Affidavit of Admission of Paternity (by the father) OR other acceptable proof of recognition (e.g., public document or father’s private handwritten instrument acknowledging paternity).
AUSF – Affidavit to Use the Surname of the Father. Who signs depends on age:
- Below 7: the mother (or person with custody) executes the AUSF.
- 7 to 17: the mother executes the AUSF with the child’s written consent.
- 18 or older: the child executes the AUSF.
Valid IDs of signatories; child’s PSA birth certificate; LCRO forms.

Where to file:

LCRO where the birth was recorded. Some LCROs accept “migrant” filings (your current LCRO forwards to the place of registration), but the birth-record LCRO is the anchor office.

Process in short:

Prepare AAP + AUSF + IDs + birth certificate.
File with the LCRO; pay fees.
LCRO evaluates, then endorses to PSA for annotation.
Once annotated, you can request a PSA birth certificate with annotation showing the change to the father’s surname.

Cost (typical ranges):

Notarization of AAP/AUSF: ₱200–₱1,000 each.
LCRO processing fee: ₱300–₱1,500 (varies by LGU).
PSA certified copy (per copy): roughly ₱150–₱400 depending on channel and delivery.
Courier/endorsement (if used): ₱150–₱500.

Timeline (realistic):

LCRO intake and endorsement: 1–3 weeks.
PSA annotation & availability of updated PSA copy: 6–12 weeks is common, up to 3–6 months in backlogs or if records are older/out-of-town.

If the father is deceased or unavailable: You may still proceed administratively if there is prior written recognition (e.g., a public document or father’s handwritten admission). If there is no recognition, RA 9255 cannot be used; you’d need to establish filiation first (often via a court case), then pursue the surname change.

3) Legitimation by the parents’ subsequent marriage

When: Parents (who were free to marry each other at conception/birth) later marry each other. Effect: Child becomes legitimate; effects retroact to birth, including use of the father’s surname. How: File an Affidavit of Legitimation with the LCRO (where the birth is recorded), attach marriage certificate and the child’s birth certificate; LCRO endorses to PSA for annotation. Cost & timeline (typical): Similar to Route 2; 2–12 weeks at LCRO/PSA depending on processing; fees commonly in the low thousands of pesos including notarization and PSA copies.

4) Judicial change of surname (Rule 103 petition in the RTC)

When:

RA 9255 does not apply (e.g., father refuses to recognize and there’s no prior written acknowledgment),
You seek to remove the father’s surname after it was adopted,
You want a hyphenated or different surname not covered administratively, or
Compelling reasons exist (confusion, ridicule, safety, long-time usage, best interests of the child).

Process in short:

Hire counsel; file a verified petition in the Regional Trial Court (RTC) where the petitioner resides.
Publication of the order once a week for 3 consecutive weeks in a newspaper of general circulation.
Notice to the Office of the Solicitor General / Prosecutor; hearing; presentation of evidence (e.g., documents, testimony, sometimes DNA in filiation cases).
If granted, the decision is recorded and endorsed to the LCRO/PSA for annotation of the birth record.

Cost & timeline (typical):

Filing & publication: ₱20,000–₱40,000+ (publication is the big line item; varies by newspaper and location).
Professional fees: highly variable (tens of thousands of pesos and up).
Total duration: commonly 6–18 months (can be shorter/longer depending on congestion and opposition).

Note: Courts decide on the best interests of the child. Philippine jurisprudence emphasizes that using the father’s surname is permissive (a privilege tied to recognition), not automatic, and courts may allow reversion to the mother’s surname or other relief if warranted by the child’s welfare.

5) Adoption (Administrative, via NACC)

When: A step-parent (or another person) adopts the child. Effect: Child becomes the legitimate child of the adopter and generally assumes the adopter’s surname. Process: Administrative adoption under RA 11642 through the NACC; after the adoption order, the LCRO/PSA annotate the birth record. Cost & timeline: Case-specific; expect months and professional fees. This route is not a shortcut just to change surnames; it’s a full legal change of filiation and status.

What each route changes—and what it doesn’t

Route	Civil status	Surname	Parental authority	Support/Inheritance
Use father’s surname (RA 9255)	Still illegitimate	Changes to father’s surname	Remains with mother (unless court orders otherwise)	Father owes support; inheritance rights of illegitimate children apply
Legitimation (parents marry)	Becomes legitimate (retroactive)	Becomes father’s surname	Follows Family Code for legitimate children (joint/over father, etc.)	Rights of legitimate children
Court-ordered change	No automatic change unless court also rules on status	As ordered by the court	No change unless separately adjudicated	No change unless separately adjudicated
Adoption	Becomes legitimate child of adopter	Adopter’s surname	As for legitimate children of adopter	As for legitimate children of adopter

Detailed RA 9255 checklist (post-registration change)

Confirm eligibility
- Child is illegitimate.
- There is express recognition by the father:
  - Father will sign an AAP, or
  - There exists a public document or private handwritten instrument signed by the father acknowledging paternity, or the birth record already shows the father’s acknowledgment.
Prepare documents
- AUSF (signatory depends on age: mother <7; data-preserve-html-node="true" mother + child consent 7–17; child if 18+).
- AAP by the father (unless recognition already appears on the birth record or via acceptable documents).
- Valid government IDs of signatories.
- PSA birth certificate of the child (latest copy).
- LCRO application forms; small photos may be asked locally.
- If a representative files, bring a Special Power of Attorney (SPA).
File and pay fees at the LCRO of registration (or migrant filing if accepted).
Track endorsement to the PSA for annotation.
Request the updated PSA birth certificate (with the marginal annotation) once available, and use this for all downstream updates.

Costs you should budget for (typical, not fixed)

Notarization (AAP/AUSF/SPAs): ₱200–₱1,000 each.
LCRO processing: ₱300–₱1,500 (some LGUs higher).
PSA copies (each): ₱150–₱400 depending on channel/delivery.
Courier/endorsement/postage (if used): ₱150–₱500.
Court route (if needed):
- Filing & publication: ₱20,000–₱40,000+
- Professional fees: varies widely (case complexity, location).

Tip: Order multiple PSA copies of the annotated record; schools, passport, banks, and agencies often need their own.

Realistic timelines

At-birth use of father’s surname: immediate at LCRO; PSA appearance often 2–6 weeks.
RA 9255 annotation (post-registration): 6–12 weeks end-to-end is common; plan for 3–6 months in slower cases.
Legitimation after marriage: often 2–12 weeks to annotate, depending on LCRO/PSA.
Court petition (Rule 103): commonly 6–18 months (longer if opposed or courts are congested).
Adoption: several months or more (case-by-case).

Special situations & FAQs

Can we switch back to the mother’s surname after using the father’s? Generally not administratively. Reversion (or choosing a different surname) usually requires a Rule 103 court petition, and the court will look at the child’s best interests.

Can we hyphenate (Mother-Father or Father-Mother)? Not a standard RA 9255 option. Hyphenation usually needs a court order showing proper and reasonable cause.

What if the father refuses to sign or denies paternity? RA 9255 cannot be used. You may consult counsel on a filiation case (evidence can include DNA) and, after recognition is judicially established, pursue the surname change.

Does using the father’s surname give the father custody or decision-making power? No. For an illegitimate child, parental authority remains with the mother unless a court orders otherwise.

What records should we update after the change?

School and academic records
PhilHealth, SSS/GSIS, Pag-IBIG
Passport (apply for reissuance under the new surname)
Bank/insurance accounts Bring the PSA birth certificate with annotation plus valid IDs and any LCRO certification.

Born abroad (reported at a Philippine consulate)? If the birth was recorded through a Report of Birth, RA 9255 changes can be processed via the Philippine Foreign Service Post that holds the record or coordinated through your LCRO/PSA once the record is in the national archives. Procedures vary slightly—ask the FSP/LCRO handling your record.

Will the father now be obliged to support the child? The duty to support exists regardless of surname once filiation is established. Surname change doesn’t reduce or increase legal support obligations; it can, however, be proof of recognition that supports a claim for support.

Quick planner

If you want the father’s surname and he’s willing to sign now: → RA 9255 annotation (or do it at birth if registering now). Fastest and cheapest.

If you want the father’s surname but he won’t cooperate (and there’s no prior written recognition): → Consider a filiation case, then proceed with the change (admin or court).

If you want to remove the father’s surname or hyphenate: → Rule 103 petition in the RTC; show best interests and compelling reasons.

If the parents are marrying (or already married) each other: → Legitimation; surname becomes the father’s as a consequence.

If a stepfather will raise the child and you want his surname: → Adoption via NACC (this changes status and surname).

Document checklist (you’ll likely need many of these)

Latest PSA birth certificate of the child
AAP (Affidavit of Admission of Paternity) or other written recognition
AUSF (Affidavit to Use the Surname of the Father)
Consent of the child (if 7–17)
Valid government IDs (father, mother, child if 18+)
Marriage certificate (for legitimation, if applicable)
SPA if a representative files
Proof of payment / ORs (LCRO, PSA)

Practical tips

Name consistency matters. After the PSA annotation, promptly update school and government records to avoid mismatches.
Keep originals & certified copies of all affidavits and receipts.
Ask your LCRO whether they accept migrant filings and what exact fees they charge.
Plan for slack time if you need the new PSA copy for a near-term passport or school enrollment—start early.

If you tell me your child’s age, where the birth was registered, and whether the father is ready to sign, I can map the exact steps and a personalized cost/time estimate for your LGU.