Changing a child’s surname in the Philippines is not a single, one-size-fits-all procedure. The correct process depends on why the surname must be changed: an illegitimate child may want to use the father’s surname, the birth certificate may contain a spelling error, the parents may have married after the child’s birth, or the requested change may affect paternity, legitimacy, adoption, or civil status. Choosing the wrong procedure can lead to rejection by the Local Civil Registry Office (LCRO), months of delay, or dismissal of a court petition.

Start by identifying the correct legal route

Before preparing affidavits or filing anything, identify which situation applies.

Situation	Usual legal route	Where to begin
An illegitimate child uses the mother’s surname and wants to use the acknowledged father’s surname	Republic Act No. 9255 and its Revised Implementing Rules	LCRO where the birth was registered, or the proper Philippine Foreign Service Post for documents executed abroad
The surname contains an obvious typing, spelling, or copying error	Republic Act No. 9048	LCRO or Philippine consulate under the applicable administrative-correction procedure
A legitimate child wants to replace the father’s surname with the mother’s surname	Rule 103 judicial change of name	Regional Trial Court
The requested change would alter paternity, legitimacy, or filiation	Appropriate direct action, often involving Rule 108 and Family Code rules	Regional Trial Court
The parents married after the child’s birth and the child qualifies for legitimation	Registration of legitimation under the Family Code	LCRO where the birth was registered
A child is to use a stepfather’s or adopter’s surname	Adoption under Republic Act No. 11642	National Authority for Child Care
The child simply uses a different surname socially, but the PSA record remains unchanged	No formal legal change yet	Appropriate administrative or judicial proceeding is still required

The most common mistake is treating every surname issue as a clerical correction. A surname cannot ordinarily be replaced through Republic Act No. 9048 merely because the family prefers another surname. That law is generally limited to harmless clerical or typographical mistakes that are obvious from the record and supporting documents. A substantial change normally requires another specific law or a court proceeding. (Lawphil)

Legal rules governing a child’s surname

Legitimate children

Article 174 of the Family Code gives legitimate children the right to bear the surnames of their father and mother in accordance with the Civil Code. Article 364 of the Civil Code states that legitimate and legitimated children shall “principally” use the father’s surname.

The Supreme Court clarified in Alanis III v. Court of Appeals that “principally” does not mean “exclusively.” A legitimate child is not absolutely prohibited from using the mother’s surname. However, this ruling does not mean that a parent can simply ask the LCRO or Philippine Statistics Authority (PSA) to replace the surname already appearing in the birth certificate. When the requested change is substantial, the proper judicial procedure and notice requirements must still be followed. The Court reiterated this principle in Santos v. Republic. See the Supreme Court decision in Alanis III v. Court of Appeals and Santos v. Republic. (Lawphil)

Illegitimate children

Article 176 of the Family Code, as amended by Republic Act No. 9255, provides that an illegitimate child generally uses the mother’s surname and remains under the mother’s parental authority. The child may use the father’s surname when the father has expressly recognized the child’s filiation through:

The child’s record of birth;
A public document; or
A private handwritten instrument signed by the father.

The word “may” is important. In Grande v. Antonio, the Supreme Court ruled that using the father’s surname is optional, not compulsory. A father cannot force an illegitimate child to use his surname merely because he has acknowledged paternity. Republic Act No. 9255 gives the child a choice under the conditions prescribed by law. Read Republic Act No. 9255 and the Supreme Court decision in Grande v. Antonio. (Lawphil)

Using the father’s surname does not by itself:

Make the child legitimate;
Transfer parental authority from the mother to the father;
Automatically grant custody to the father;
Eliminate the father’s obligation to provide support; or
Create or remove inheritance rights independently of legally established filiation.

The surname appearing on the birth certificate is evidence of identity, but it is not a substitute for the Family Code rules on legitimacy, filiation, custody, support, and succession.

How an illegitimate child can use the father’s surname under RA 9255

Republic Act No. 9255 is usually the simplest route when the child was born outside a valid marriage, the father has acknowledged the child, and the only objective is to use the father’s surname.

The detailed procedure is found in the PSA’s 2016 Revised Implementing Rules and Regulations of Republic Act No. 9255. (Philippine Statistics Authority)

1. Confirm that the father has legally acknowledged the child

The father must have acknowledged filiation through one of the legally accepted documents. Depending on how and when the acknowledgment was made, the supporting document may include:

An Affidavit of Acknowledgment or Admission of Paternity;
A Private Handwritten Instrument, or PHI, personally written and signed by the father;
A public document in which the father expressly recognizes the child; or
The birth record itself, if the father properly acknowledged the child when the birth was registered.

A father’s name appearing informally in school records, social-media posts, remittance receipts, or family photographs is not a substitute for the acknowledgment required by Article 176 and the RA 9255 rules.

2. Determine who must sign the Affidavit to Use the Surname of the Father

The document that authorizes use of the father’s surname is commonly called the AUSF, or Affidavit to Use the Surname of the Father.

Who signs depends on the child’s age at the time the AUSF is executed:

Child’s age	Person who executes the AUSF
Birth to 6 years old	The mother; in her absence, the child’s guardian
7 to 17 years old	The child, with an attestation by the mother or guardian that the child understands the consequences
18 years old or older	The child personally, without the mother’s attestation

This age distinction is frequently overlooked. For example, a mother cannot ordinarily execute the AUSF in place of a 15-year-old child. The child must personally make the choice, subject to the required attestation. (Philippine Statistics Authority)

3. Prepare the required documents

Exact checklists vary slightly among LCROs, but the usual documents include:

PSA or LCRO copy of the child’s Certificate of Live Birth;
Valid identification documents of the person signing the AUSF;
Affidavit of Acknowledgment or Admission of Paternity, if acknowledgment is not already properly recorded;
The father’s private handwritten instrument, if that is the basis of acknowledgment;
The duly notarized AUSF;
Proof of guardianship when a guardian acts for a child below seven;
Supporting registration forms required by the LCRO; and
Applicable filing or registration fees.

The LCRO may require the original document, certified copies, specimen signatures, or additional proof that the person appearing before the registrar is the same person named in the civil-registry record.

4. File the documents in the proper place

For a birth registered in the Philippines, documents executed in the Philippines are generally registered with the LCRO of the city or municipality where the child’s birth was recorded.

When documents are executed abroad, registration may be made through the Philippine embassy or consulate having jurisdiction over the place of residence, or the nearest Philippine Foreign Service Post. If the birth occurred abroad but the document is executed in the Philippines, the rules may allow registration with the LCRO of the place where the document was executed. The appropriate consulate or LCRO should be consulted because routing and documentary requirements can differ. (Philippine Statistics Authority)

5. Register the acknowledgment and AUSF promptly

The Revised Rules state that the acknowledgment document and AUSF should be registered within 20 days from execution. Documents submitted after that period are generally processed under delayed-registration requirements, which may involve additional affidavits, supporting evidence, posting, or local procedures. (Philippine Statistics Authority)

This does not necessarily mean that the child loses the right to use the father’s surname after 20 days. It means the registration becomes procedurally more complicated.

6. Wait for annotation and PSA endorsement

Once accepted, the LCRO records the acknowledgment and AUSF, annotates the local birth record, and endorses the documents to the PSA. The PSA then processes the annotation in its central civil-registry database.

The annotated birth certificate normally shows a marginal annotation stating that the child is authorized to use the father’s surname under Republic Act No. 9255. The original entries are not simply erased as though they never existed.

The PSA offers a premium annotation service at participating locations for qualified and complete transactions. The published PSA fee is ₱255 per document, with release targeted within 10 working days after complete documents are accepted for premium processing. This is not the total end-to-end timeline: LCRO registration, local annotation, transmittal, verification, and correction of deficiencies can take additional weeks or months. See the PSA information on premium annotation services. (Philippine Statistics Authority)

7. Check how the child’s middle name will appear

Under PSA Memorandum Circular No. 2020-28, an illegitimate child born in the Philippines who is not recognized by the father normally has no middle name. The same generally applies when the father has acknowledged the child but no valid AUSF has been registered.

When a valid AUSF is registered and the child uses the father’s surname, the mother’s maiden surname generally becomes the child’s middle name.

For example:

Before AUSF: Maria Santos
After valid AUSF: Maria Reyes Santos, where “Reyes” is the mother’s maiden surname and “Santos” is the father’s surname

The result depends on the exact entries and supporting records, particularly for children born abroad.

Can the father force the child to use his surname?

No. The Supreme Court’s ruling in Grande v. Antonio makes clear that Republic Act No. 9255 permits, but does not compel, use of the father’s surname.

For a child below seven, the mother or, in her absence, the guardian executes the AUSF. For a child aged seven to seventeen, the child personally executes it with the required attestation. An adult child decides personally.

The father’s acknowledgment remains legally important even if the child continues using the mother’s surname. Acknowledged filiation may affect support, succession, and other rights, but it does not give the father an automatic right to dictate the child’s surname. (Lawphil)

How to correct a misspelled surname under RA 9048

Republic Act No. 9048 authorizes administrative correction of a clerical or typographical error in a civil-registry entry. A clerical error is generally a harmless mistake that is obvious and can be corrected by reference to existing records without deciding a disputed legal issue.

Examples may include:

“Dela Crux” instead of “Dela Cruz”;
One missing letter caused by a typing error;
A transposed letter that clearly conflicts with the parents’ records; or
An encoding mistake made during registration.

The petitioner normally files with the LCRO where the birth was registered. A migrant petition may be permitted when the petitioner now lives elsewhere, subject to endorsement and additional local requirements. Filipinos abroad may file through the appropriate Philippine embassy or consulate.

Supporting records commonly include:

The birth certificate containing the error;
The parents’ birth and marriage records;
School, baptismal, medical, or employment records showing consistent usage;
Valid identification documents;
A police or National Bureau of Investigation clearance when required;
Affidavits explaining the discrepancy; and
Other records requested by the civil registrar.

The PSA’s published administrative filing fee for correction of a clerical or typographical error under RA 9048 is ₱1,000, excluding possible local, migrant-petition, notarization, document, publication, or consular charges. See the PSA schedule and requirements for administrative petitions. (Philippine Statistics Authority)

RA 9048 cannot be used merely to replace one legally correct surname with another preferred surname. If evidence must be weighed to decide paternity, legitimacy, adoption, or a contested identity, the matter is substantive and usually requires a different proceeding.

How to file a judicial petition to change a child’s surname

When no administrative law authorizes the requested change, the usual remedy is a judicial petition under Rule 103 of the Rules of Court.

Examples include:

A legitimate child seeking to use the mother’s surname instead of the father’s surname;
A child seeking to revert to a former surname after a registered AUSF;
Removal of a surname that causes serious confusion or embarrassment;
A substantial surname change not based on a clerical error;
A change connected with legitimation, adoption, or another legal consequence when the applicable procedure requires judicial action; or
A request based on the child’s long-standing and consistent use of another surname.

1. Evaluate whether there is a proper and reasonable cause

Changing a name is not an absolute right. Courts consider whether the reason is substantial, honest, and consistent with the child’s welfare and the public interest.

Recognized grounds discussed in Supreme Court decisions include:

The name is ridiculous, dishonorable, or extremely difficult to write or pronounce;
The change is a legal consequence of legitimation or adoption;
The change will avoid confusion;
The present surname causes serious embarrassment;
The person has continuously and publicly used another name;
The request is made in good faith and will not prejudice another person; or
Other circumstances show that the change serves the child’s best interests.

When the subject is a minor, the court’s central concern is not the preference or resentment of either parent. It is the child’s welfare. In Calderon v. Republic, the Supreme Court emphasized that changing an infant’s name should be allowed only when it is clearly shown to be in the child’s best interest. See Calderon v. Republic. (Lawphil)

2. File a verified petition in the proper Regional Trial Court

Rule 103 requires the petition to be filed in the Regional Trial Court of the province or city where the petitioner resides.

The petition must ordinarily state:

The child’s full registered name;
Any aliases or other names used;
The child’s residence;
The required period of bona fide residence;
The specific reason for the requested change;
The exact new name or surname requested;
The identities and circumstances of the parents or legal representatives;
The absence of fraudulent or unlawful purpose; and
Why the change is in the child’s best interest.

The petition is verified, meaning that the petitioner swears that the material allegations are true based on personal knowledge or authentic records.

For a minor, the petition is normally brought through the appropriate parent, guardian, or legal representative. Questions concerning parental authority, custody, conflict of interest, and notice to the other parent must be addressed carefully.

3. Obtain the court’s order setting the hearing

If the petition is sufficient in form, the court issues an order stating the purpose of the petition and setting the date and place of hearing.

The caption and published order must accurately identify the child’s registered name, relevant aliases, and proposed name. Serious errors or omissions can affect the court’s jurisdiction because the publication is meant to notify the government and any person who may be affected.

4. Publish the court order

Rule 103 requires publication of the order once a week for three consecutive weeks in a newspaper of general circulation designated by the court.

Publication is not a minor technicality. It is a jurisdictional safeguard. Failure to publish correctly may result in dismissal or make the judgment vulnerable to challenge.

The hearing cannot be scheduled within 30 days before an election and cannot be held until at least four months after the last publication. These waiting periods alone explain why a Rule 103 case cannot ordinarily be completed in only a few weeks. Review Rules 103 and 108 of the Rules of Court. (Lawphil)

5. Present evidence at the hearing

Evidence may include:

The child’s PSA birth certificate;
The parents’ civil-registry records;
School, medical, religious, travel, or government records;
Proof of the surname the child has consistently used;
Testimony from the parent, guardian, child, relatives, teachers, or other witnesses;
Evidence of confusion, embarrassment, abandonment, or other claimed hardship;
Proof that the change will not conceal criminal, financial, immigration, or civil liabilities; and
Evidence showing that the requested surname is in the child’s best interest.

The Office of the Solicitor General, public prosecutor, local civil registrar, PSA, another parent, or other interested persons may oppose the petition.

6. Secure a final judgment and annotate the civil-registry record

If the court grants the petition, the decision must become final. The petitioner then obtains certified copies of the final decision, certificate of finality, and the court’s registration or implementation orders.

These documents are submitted to the proper LCRO and transmitted to the PSA for annotation. A favorable judgment does not update the PSA record automatically; post-judgment registration and endorsement must still be completed.

Practical timeline and cost

An uncontested Rule 103 petition may take roughly six to eighteen months in practice, depending on the court’s calendar, publication schedule, completeness of evidence, opposition, and PSA processing. Contested or procedurally defective cases can take considerably longer.

Typical expenses include:

Court filing and legal research fees;
Sheriff, mailing, and service expenses;
Newspaper publication, often the largest mandatory expense;
Certified copies and civil-registry documents;
Notarization;
Transcript or stenographic fees when applicable;
LCRO and PSA annotation expenses; and
Professional fees when counsel is engaged.

There is no reliable nationwide fixed total. Court fees, newspaper rates, and local civil-registry charges vary significantly by location.

When the surname issue involves paternity or legitimacy

Some cases appear to be requests for a surname change but are actually disputes over filiation, the legal relationship between a child and a parent, or legitimacy, the child’s status under the Family Code.

Child born while the mother was married to another man

Under Article 164 of the Family Code, a child conceived or born during a valid marriage is generally presumed legitimate. Article 167 further provides that the child’s legitimacy is not affected merely by the mother’s declaration against legitimacy or by a judgment that she committed adultery.

This means the biological father cannot simply execute an acknowledgment and AUSF to replace the husband’s surname. The presumption of legitimacy must first be addressed through the direct action allowed by law, brought by the proper party and within the strict periods under Articles 170 and 171 of the Family Code.

The Supreme Court has repeatedly warned that legitimacy and filiation cannot be attacked indirectly through a simple Rule 108 correction case or an administrative request to change the birth certificate. In cases such as Miller v. Miller and Republic v. Cua Ko, the Court stressed the special rules protecting a child’s civil status. (Lawphil)

Wrong father entered in the birth certificate

Removing or replacing the person recorded as the father is not a clerical correction. It may affect:

The child’s legitimacy;
Parental authority;
Support;
Succession and inheritance;
Citizenship;
Immigration status; and
The rights of the recorded father, biological father, mother, and child.

A substantial correction under Rule 108 must be handled as an adversarial proceeding, with proper notice to all affected parties and an opportunity to oppose. In some cases, a separate direct action concerning filiation or legitimacy is required before the civil-registry entry can be changed.

DNA evidence can be important, but it does not automatically override statutory presumptions or cure the use of an improper procedure.

What happens when the parents marry after the child’s birth?

A child born outside marriage may qualify for legitimation when the statutory conditions under the Family Code are satisfied and the parents subsequently enter into a valid marriage.

Legitimation gives the child the rights of a legitimate child from birth, subject to the governing law. However, the parents’ marriage does not automatically update the PSA birth certificate.

The parents must register the legitimation with the LCRO where the child’s birth was recorded. The usual documents include:

The child’s birth certificate;
The parents’ marriage certificate;
Affidavit or joint instrument of legitimation;
Proof that the legal requirements for legitimation were met;
Valid identification documents; and
Other records required by the civil registrar.

After registration and PSA annotation, the child’s name and civil status are reflected according to the applicable legitimation rules.

Parents should not use an AUSF as a substitute when the proper transaction is legitimation. The two procedures have different legal effects: an AUSF concerns use of the acknowledged father’s surname by an illegitimate child, while legitimation changes the child’s civil status.

Can a child use a stepfather’s surname?

A stepfather cannot ordinarily give his surname to a child merely through an affidavit, school enrollment form, or private family agreement.

When the intention is to establish a permanent legal parent-child relationship, the proper route is generally stepparent adoption under Republic Act No. 11642, the Domestic Administrative Adoption and Alternative Child Care Act of 2022.

Domestic adoption is now primarily administrative and is handled by the National Authority for Child Care, or NACC. A completed adoption may result in an amended birth certificate showing the adopter as a parent and allowing the child to use the adopter’s surname as an incident of adoption. See Republic Act No. 11642 and the National Authority for Child Care. (Lawphil)

The consent of the biological parent, the child’s age, abandonment or death of a parent, custody arrangements, and the child’s best interests can materially affect the process. Using a stepfather’s surname socially does not itself create adoption, inheritance rights, parental authority, or an amended PSA record.

Required documents, fees, and realistic timelines

Procedure	Common documents	Government fees and other costs	Practical timeline
RA 9255 acknowledgment and AUSF	Birth certificate, acknowledgment document, AUSF, IDs, guardianship proof if applicable	LCRO fees vary by LGU; notarization and document costs; PSA premium annotation is ₱255 where available	Several weeks to a few months, depending on LCRO endorsement and PSA processing
RA 9048 correction of surname typo	Birth certificate, parents’ records, IDs, school or baptismal records, affidavits and clearances when required	PSA-published petition fee is ₱1,000, plus local, migrant, notarization, and document charges	Commonly a few months; longer if records conflict or the petition is posted or endorsed elsewhere
Rule 103 judicial change of surname	Verified petition, birth certificate, supporting records, witness evidence and publication	Court fees, publication, certified copies, annotation costs and possible professional fees	Often six to eighteen months if uncontested; longer if opposed
Legitimation	Birth and marriage certificates, instrument of legitimation, IDs and proof of eligibility	Local registration and PSA annotation fees vary	Several weeks to several months
Adoption under RA 11642	NACC forms, civil-registry records, consents, clearances, assessments and supporting evidence	Costs vary according to required documents, evaluations and post-order registration	Often many months; complex or contested cases take longer

Local civil-registry fees are set under local ordinances and citizen’s charters. There is no single nationwide AUSF or legitimation fee. Always obtain the current checklist and fee schedule from the LCRO that will receive the documents.

Common mistakes that cause rejection or delay

Using RA 9048 for a substantial surname change

RA 9048 is not a general shortcut for changing a child’s surname. It applies to genuine clerical or typographical errors, not disputed parentage or a change based only on preference.

Assuming acknowledgment automatically changes the surname

A father’s acknowledgment establishes a basis for filiation, but the child does not automatically begin using the father’s surname. A valid AUSF must still be executed and registered under the applicable age rules.

Ignoring the child’s age

The identity of the proper AUSF signatory changes when the child turns seven and again when the child turns eighteen. Using the wrong signatory can result in rejection.

Signing an AUSF without understanding its lasting effect

A registered AUSF should not be treated as a temporary school-record adjustment. An LCRO will not ordinarily erase or cancel it simply because a parent later changes their mind. Reverting to the mother’s surname may require an appropriate judicial petition.

Treating a surname change as proof of custody

A surname does not determine custody. An illegitimate child’s use of the father’s surname does not automatically transfer parental authority from the mother under Article 176.

Failing to register the final court order

Winning a case is only one stage. The final decision and certificate of finality must still be registered with the LCRO and endorsed to the PSA.

Using inconsistent names across records too early

Changing school, passport, immigration, banking, or medical records before obtaining the annotated PSA certificate can create further discrepancies. The safest sequence is usually to complete the civil-registry process first and then update other agencies using the annotated record.

Filing a simple name-change case when legitimacy is disputed

When a child was born during an existing marriage, or when the recorded father is being removed or replaced, the court must address the Family Code rules on legitimacy and filiation. A Rule 103 name-change petition alone may be legally insufficient.

Children born abroad and foreign documents

For a Filipino child born abroad, the controlling Philippine record is usually the Report of Birth registered through the Philippine embassy or consulate and transmitted to the PSA.

The applicable procedure depends on:

Where the child was born;
Where the birth or Report of Birth was registered;
Where the acknowledgment or AUSF is executed;
The child’s citizenship;
Whether the foreign birth record already contains a middle name or surname;
Whether the father is Filipino or foreign; and
Whether foreign documents are in English.

Foreign public documents may need an apostille under the Apostille Convention or diplomatic or consular authentication when the issuing country is not covered by the convention. Documents executed before a Philippine consular officer may instead follow the consulate’s notarization rules. A certified translation may be required for documents in another language.

The relevant Philippine Foreign Service Post should be asked for its current checklist before documents are signed, because notarization, personal-appearance, apostille, translation, and mailing requirements vary by country.

A foreign name-change order does not necessarily amend a Philippine civil-registry record automatically. Philippine recognition, registration, or an appropriate local proceeding may still be required, depending on the nature of the order and the civil-status issue involved.

Frequently Asked Questions

Can a mother change her child’s surname to the father’s surname without the father’s consent?

If the father has already validly acknowledged the child, the mother may execute the AUSF for a child below seven under the RA 9255 rules. However, she cannot create or fabricate the father’s acknowledgment. For a child aged seven to seventeen, the child must execute the AUSF with the required attestation. An adult child decides personally.

Can an illegitimate child use the father’s surname even if the parents are not married?

Yes. Republic Act No. 9255 permits an illegitimate child to use the acknowledged father’s surname even without marriage, provided the acknowledgment and AUSF requirements are satisfied.

Can the father force an illegitimate child to use his surname?

No. Under Grande v. Antonio, the use of the father’s surname is permissive rather than mandatory. Acknowledging the child does not give the father an absolute right to impose his surname.

Can the child use the father’s surname if the father has not acknowledged paternity?

Not through RA 9255. Express acknowledgment in the birth record, a public document, or a private handwritten instrument is required. When paternity is disputed, a court action to establish filiation may be necessary.

Can the mother remove the father’s surname after an AUSF has been registered?

Usually not through a simple request to the LCRO. A registered AUSF forms part of the civil-registry record. Reverting to the mother’s surname will ordinarily require a proper judicial proceeding or another legally applicable remedy.

Does using the father’s surname make an illegitimate child legitimate?

No. Use of the surname and legitimacy are separate legal matters. Legitimation generally requires the statutory conditions and the parents’ subsequent valid marriage, followed by registration of the legitimation.

Does changing the surname affect child support or inheritance?

Not by itself. Support and succession rights depend primarily on legally established filiation and the applicable Family Code and Civil Code provisions. A father cannot avoid support simply because the child uses the mother’s surname.

Can a legitimate child use the mother’s surname?

Yes, Philippine law does not absolutely prohibit it, as explained in Alanis III v. Court of Appeals. However, replacing the surname already recorded in the birth certificate normally requires a Rule 103 judicial petition and proof of a proper and reasonable cause.

Can a child use a stepfather’s surname without adoption?

Generally, not as a formal civil-registry change based solely on the stepfather’s affidavit or consent. Stepparent adoption under Republic Act No. 11642 is usually the proper process when the family intends to create a legal parent-child relationship.

How long does it take to change a child’s surname?

An uncomplicated RA 9255 or clerical-correction transaction may take several weeks to a few months after complete filing. A judicial name-change case commonly takes six to eighteen months or longer because of publication, mandatory waiting periods, hearings, finality, and PSA annotation.

Will the PSA issue a completely new birth certificate?

For many corrections and surname changes, the PSA issues a copy of the original record containing an annotation of the approved change. Adoption is different: the law may authorize an amended birth certificate, while the original record is handled according to adoption confidentiality rules.

Key Takeaways

The correct procedure depends on the legal reason for changing the child’s surname.
An illegitimate child may use the acknowledged father’s surname through Republic Act No. 9255 and a properly registered AUSF.
The father cannot force an illegitimate child to use his surname.
A spelling or typing mistake may be corrected administratively under Republic Act No. 9048, but a substantial surname replacement usually cannot.
A legitimate child may use the mother’s surname, but changing the PSA record normally requires a Rule 103 court petition.
Questions involving paternity, legitimacy, or removal of a recorded father require more than a simple name-change request.
The parents’ later marriage requires formal registration of legitimation; the PSA record does not update automatically.
A child generally cannot acquire a stepfather’s surname through a private affidavit alone; legal adoption is usually required.
A surname change does not by itself determine legitimacy, parental authority, custody, support, or inheritance.
After approval, the court order, AUSF, legitimation, or other instrument must still be registered and properly endorsed to the PSA.