In the Philippines, a child's surname forms a core part of their legal identity, reflecting legitimacy, filiation, and family relations under the Civil Code and Family Code. Legitimate children principally bear the father's surname, while illegitimate children generally use the mother's surname unless the father acknowledges paternity. Changing a minor child's surname is not a matter of parental convenience or right but requires valid legal grounds and adherence to strict procedures, always prioritizing the child's best interest as parens patriae. Changes occur through administrative mechanisms in limited cases or judicial proceedings for substantial alterations.

Legal Framework

The primary laws governing surnames include:

Civil Code of the Philippines (Articles 364–380) — Regulates the use and change of surnames.
Family Code of the Philippines (Executive Order No. 209, as amended) — Defines rules on legitimacy, parental authority, and filiation (e.g., Article 176 on surnames of illegitimate children).
Republic Act No. 9255 (RA 9255) — Amends Article 176 to allow illegitimate children to use the father's surname upon proper acknowledgment.
Republic Act No. 9048, as amended by RA 10172 — Authorizes the local civil registrar (LCR) or consul to correct clerical or typographical errors and change first names or nicknames administratively, without court intervention. Surname changes generally fall outside its scope unless they involve mere spelling corrections.
Rules of Court:
- Rule 103 (Change of Name) — Applies to petitions seeking a new surname based on compelling reasons.
- Rule 108 (Cancellation or Correction of Entries in the Civil Registry) — Used for substantial corrections to civil registry entries, including erroneous surnames.

Jurisprudence consistently holds that a change of name or surname is not a right but subject to judicial discretion. The petitioner must demonstrate proper and reasonable cause, such as when the surname is ridiculous, dishonorable, extremely difficult to pronounce or write, causes confusion, or when the change serves the child's welfare (e.g., to avoid embarrassment or stigma). The court evaluates whether the change prejudices public interest or involves fraud.

Common Scenarios for Changing a Child's Surname

1. Legitimation by Subsequent Marriage of Parents

When parents marry after the child's birth, the child is legitimated under Article 177–178 of the Family Code and acquires the right to the father's surname. This is an administrative process:

The parents execute an Affidavit of Legitimation.
Submit to the LCR where the birth was registered: the child's birth certificate, parents' marriage certificate, and supporting documents (e.g., valid IDs).
The LCR annotates the birth record to reflect legitimation and the new surname.
Obtain an updated PSA-certified birth certificate.

No court petition is required if documents are complete. The original surname entry remains but is annotated.

2. Acknowledgment by the Father (Illegitimate Child Using Father's Surname)

Under RA 9255, an illegitimate child may use the father's surname if the father acknowledges paternity through a public document (e.g., Affidavit of Admission of Paternity) or private handwritten instrument.

For children 6 years old and below: The mother executes the Affidavit to Use the Surname of the Father (AUSF).
For children 7–17 years old: The child executes the AUSF with the mother's attestation.
For those 18 and above: The individual executes it independently.
File the AUSF and acknowledgment document with the LCR of birth registration, along with the birth certificate and IDs.
The LCR updates the record; the child may then use the father's surname.

If the father refuses or no acknowledgment exists, the child retains the mother's surname.

3. Adoption

Adoption provides a direct path to surname change. Under the Domestic Adoption Act of 1998 (RA 8552) or relevant rules:

The adoptive parent(s) file a petition for adoption in the appropriate Family Court or RTC.
Upon issuance of the adoption decree (which becomes final), the child generally takes the adoptive parent's (or parents') surname.
The court order serves as the basis for the LCR to issue a new or annotated birth certificate reflecting the adoptive surname and parentage.
In step-parent adoptions, the child may retain elements of the original surname or fully adopt the new one as ordered.

This process integrates the surname change; a separate name-change petition is unnecessary and, in fact, discouraged as the proceedings must remain distinct.

4. Judicial Change of Name (Rule 103) – Most Common for Substantial Surname Changes

When administrative remedies do not apply (e.g., changing from father's to mother's surname due to abandonment, neglect, non-support, or to protect the child's welfare), a petition under Rule 103 is required.

Valid Grounds (Non-Exhaustive, Based on Jurisprudence and Best Interest of the Child):

The surname is ridiculous, dishonorable, or extremely difficult to write/pronounce.
The change avoids confusion or embarrassment.
Parental abandonment or prolonged absence by the father, with no support or involvement, causing stigma or psychological harm to the child.
Safety concerns (e.g., domestic violence or risk associated with the surname).
The child has been known and used another surname continuously since childhood.
Other compelling reasons showing the change serves the child's welfare (e.g., the mother has sole custody and the father has forfeited parental rights).

Courts require clear and convincing evidence; mere preference is insufficient. For minors, the child's maturity and preference (especially if 7 years or older) may be considered.

Who May File: The mother, legal guardian, or person with direct interest files on behalf of the minor. The other parent receives notice; consent is ideal but not always required if abandonment or unfitness is proven.

5. Correction of Erroneous Entry (Rule 108 or RA 9048 if Clerical)

If the surname on the birth certificate was entered due to a clerical or typographical error (e.g., misspelling or interchanged names), correction is possible:

Administrative (RA 9048/10172): For pure clerical errors, file a petition directly with the LCR. Requires at least two supporting documents showing the correct entry.
Judicial (Rule 108): For substantial corrections affecting filiation or legitimacy, file in RTC as an adversarial proceeding with publication.

Requirements and Documents for Judicial Petition (Rule 103)

Verified petition stating: the child's personal circumstances, current and proposed surname, detailed grounds/reasons, and an affirmation that the change is not for fraudulent purposes (e.g., evading obligations).
Supporting documents (certified true copies where applicable):
- Child's birth certificate (PSA).
- Proof of grounds (e.g., affidavits of witnesses to abandonment, lack of support records, school documents, psychological evaluation if relevant, barangay clearances, NBI clearance).
- Petitioner's valid government IDs and proof of relationship/guardianship.
- Marriage certificate (if applicable).
- Proof of residence (e.g., barangay certificate).
- Judicial affidavits of the petitioner and witnesses.
For abandonment cases: Evidence of willful failure to provide support or maintain contact over a significant period.

Step-by-Step Court Process (Rule 103)

Preparation and Filing — Consult a lawyer to draft the petition. File in the Regional Trial Court (RTC) of the place where the child resides (or, in some interpretations, where the civil registry is located). Pay docket and legal fees.
Court Order for Publication — The court issues an order directing publication of the petition and hearing notice in a newspaper of general circulation once a week for three consecutive weeks. This gives interested parties (including the other parent) an opportunity to oppose.
Service of Notices — Copies are served on the Office of the Solicitor General (OSG), the Local Civil Registrar, and the other parent (at last known address).
Hearing — After publication, the court conducts a hearing. The petitioner presents evidence and witnesses. The State (through the prosecutor or OSG) may participate to protect public interest. The court assesses the sufficiency of grounds and the child's best interest.
Decision — If granted, the court issues a decision ordering the LCR to change or annotate the surname in the civil registry. The decision becomes final after the period for appeal or motion for reconsideration lapses.
Registration and Implementation — Register the court decision with the LCR where the birth was recorded and with the PSA. The LCR annotates the birth certificate or issues a corrected one. Obtain multiple PSA-certified copies.
Post-Change Updates — Update the child's records in school, passport (DFA), PhilHealth, SSS, bank accounts, and other government agencies. Failure to update can cause practical difficulties.

The entire judicial process typically takes several months to over a year, depending on court dockets, publication scheduling, and any oppositions.

Costs and Practical Considerations

Filing and Docket Fees — Start at around ₱5,000 or more, varying by court.
Publication Costs — ₱20,000 or higher for three weekly insertions in a qualified newspaper.
Legal Fees — Lawyer's professional fees depend on complexity; representation is strongly recommended.
Miscellaneous — Notary, sheriff, expert witnesses (e.g., psychologist), and PSA/LCR fees.

Challenges include proving abandonment convincingly, potential opposition from the biological father, and ensuring the change does not inadvertently affect inheritance or filiation rights (surname change alone does not alter legitimacy status). Courts exercise caution to prevent fraudulent or capricious changes.

Effects of the Change

A granted surname change updates the official civil registry record but does not erase the historical entry (it is annotated). The child's legal filiation, citizenship, and inheritance rights remain based on blood relations or adoption decree, not the surname alone. The new surname applies for all future official purposes once records are updated.

For minors, the process underscores the paramount consideration of the child's welfare, psychological well-being, and protection from harm or stigma associated with the original surname. In all cases—whether administrative or judicial—compliance with procedural requirements is mandatory to ensure the validity and enforceability of the change.