Yes. An illegitimate child in the Philippines may use the father’s surname, but only if the legal requirements are met. The father must have expressly recognized the child, and the proper civil registry documents must be filed. The child does not automatically get the father’s surname just because the father is named, biologically known, or financially supporting the child. The process usually involves the Local Civil Registry Office, the Philippine Statistics Authority, and, for children born abroad, the Philippine Embassy or Consulate.
The Basic Rule: An Illegitimate Child Usually Uses the Mother’s Surname
Under Philippine law, a child is generally considered illegitimate if the child was conceived and born outside a valid marriage.
The starting rule is found in Article 176 of the Family Code, as amended by Republic Act No. 9255 (2004):
Illegitimate children shall use the surname and shall be under the parental authority of their mother.
This means that, by default, an illegitimate child uses the mother’s surname.
But RA 9255 created an important exception: an illegitimate child may use the father’s surname if the father expressly recognizes the child in the way required by law.
You can read the full text of Republic Act No. 9255 on Lawphil.
What RA 9255 Allows
RA 9255 does not make an illegitimate child legitimate. It also does not give the father automatic custody or parental authority.
It only allows the child to use the father’s surname when the father has legally acknowledged the child.
Under Article 176, the child may use the father’s surname if filiation is expressly recognized by the father through:
- The record of birth appearing in the civil register
- An admission in a public document
- An admission in a private handwritten instrument made by the father
In simple terms, the father must clearly admit in writing that he is the child’s father.
“May Use” Means It Is Optional, Not Mandatory
A very important point: the law says an illegitimate child may use the father’s surname. It does not say the child must use it.
In Grande v. Antonio, G.R. No. 206248, February 18, 2014, the Supreme Court explained that the use of the father’s surname under RA 9255 is permissive, not compulsory. The father cannot force the child to use his surname.
The Supreme Court also emphasized that Article 176 gives the right to the child, not to the father. The father’s acknowledgment is required, but it does not give him the power to impose his surname against the proper consent or process.
The full decision is available through the Supreme Court E-Library case page for Grande v. Antonio.
What Counts as the Father’s Recognition?
The father’s recognition must be clear, express, and in a proper document. It is not enough that people in the family know he is the father.
Common valid forms of recognition
| Form of recognition | Practical example | Usually enough for RA 9255? |
|---|---|---|
| Signature on the Certificate of Live Birth | Father signs the acknowledgment portion of the birth certificate | Yes, if properly registered |
| Affidavit of Admission of Paternity | Father signs a notarized affidavit admitting he is the father | Yes |
| Private Handwritten Instrument | Father writes and signs a handwritten statement admitting paternity | Yes, subject to stricter filing and supporting documents |
| Court judgment declaring paternity | Court finds that the man is the father | May support correction, but often requires a court-based process rather than simple AUSF |
| Verbal admission | Father tells relatives or friends he is the father | No |
| Financial support alone | Father pays expenses but signs nothing | Usually no |
| Name of father typed on birth certificate but no signature or proper acknowledgment | Father’s name appears but acknowledgment is defective | Often not enough by itself |
The 2016 Revised Implementing Rules and Regulations of RA 9255 define a Private Handwritten Instrument as a document in the father’s handwriting, signed by him, where he expressly recognizes the child during his lifetime. The same rules define the Affidavit to Use the Surname of the Father, or AUSF, as the registrable document executed so the child can use the father’s surname. The PSA version of the rules is available on the Philippine Statistics Authority RA 9255 page.
What Is an AUSF?
An AUSF means Affidavit to Use the Surname of the Father.
This is the document used to tell the civil registrar that the illegitimate child will use the father’s surname under RA 9255.
The AUSF is especially important when:
- the child’s birth was already registered under the mother’s surname;
- the father later executed an acknowledgment;
- the father acknowledged the child in a separate affidavit;
- the father acknowledged the child through a private handwritten instrument;
- the child was born abroad and the Report of Birth needs to reflect or be annotated with the father’s surname.
The PSA explains that when the birth certificate is already registered under the mother’s surname and the father later executes an affidavit of acknowledgment, the affidavit of acknowledgment and the AUSF should be registered with the civil registry office where the child’s birth was registered. See the PSA guidance on a birth certificate already registered under the mother’s surname.
Who Can File the Documents?
Under the RA 9255 rules, the following may file the Affidavit of Admission of Paternity or the AUSF:
- the father;
- the mother;
- the child, if of legal age;
- the guardian.
For a Private Handwritten Instrument, the father generally must personally file it if he is alive. If the father is already deceased, the mother, the child of legal age, or the guardian may file it, but the civil registrar may require supporting documents to prove filiation.
Does the Child’s Age Matter?
Yes. The child’s age affects who must execute or participate in the AUSF.
| Age of child | Who usually executes or participates in the AUSF |
|---|---|
| 0 to 6 years old | Mother, or guardian if the mother is absent |
| 7 to 17 years old | Child executes the AUSF, fully aware of its consequences, with attestation by the mother or guardian |
| 18 years old and above | Child executes the AUSF personally, without need of attestation |
This reflects the rule that the use of the father’s surname is tied to the child’s right and identity, not merely the father’s preference.
Step-by-Step: How an Illegitimate Child Can Use the Father’s Surname
The exact process can vary slightly by city or municipality, but the practical flow is usually the same.
1. Check the child’s PSA birth certificate or local civil registry record
Start with the child’s birth record.
Check:
- Is the birth already registered?
- Is the child currently using the mother’s surname?
- Is the father named?
- Did the father sign the acknowledgment portion?
- Is there already an annotation?
- Are there spelling errors in the child’s name, mother’s name, or father’s name?
It is often useful to check both:
- the PSA-issued birth certificate, and
- the local civil registry copy from the city or municipality where the birth was registered.
Sometimes the LCRO has a clearer or more complete record than the PSA copy.
2. Determine if the father has legally acknowledged the child
If the father signed the acknowledgment portion of the Certificate of Live Birth, that may be enough recognition.
If not, he may need to execute an:
- Affidavit of Admission of Paternity, or
- other public document expressly recognizing the child, or
- Private Handwritten Instrument expressly recognizing the child.
If the father refuses to sign anything, the administrative RA 9255 route usually cannot proceed. In that situation, the issue may shift from a surname process to a paternity or filiation case, where the child seeks to legally establish the father-child relationship.
3. Prepare the AUSF
The AUSF should be prepared using the form accepted by the LCRO or Philippine Foreign Service Post.
It usually states:
- the child’s current registered name;
- the child’s birth details;
- the father’s acknowledgment document;
- the surname to be used;
- the legal basis under RA 9255;
- the signature of the proper person, depending on the child’s age.
Do not rely on a generic affidavit downloaded online if the LCRO or Consulate has its own preferred form. Many offices follow the revised RA 9255 form.
4. File at the correct office
Where you file depends on where the birth occurred and where the documents were executed.
| Situation | Where to file |
|---|---|
| Child born in the Philippines; documents executed in the Philippines | LCRO of the child’s place of birth |
| Child born abroad; documents executed abroad | Philippine Embassy or Consulate with jurisdiction |
| Child born abroad; documents executed in the Philippines | LCRO of the place where the document was executed |
| Birth already registered under mother’s surname | Usually LCRO where the birth was registered |
| Birth abroad already reported to a Philippine Embassy or Consulate | Philippine Foreign Service Post or PSA annotation process, depending on the record |
The 2016 RA 9255 rules refer to the LCRO for local filings and the PFSP for filings abroad. PFSP means Philippine Foreign Service Post, such as a Philippine Embassy or Consulate.
5. Register the acknowledgment and AUSF
The civil registrar or consular officer examines the documents.
If accepted, the office records the documents in the proper registry, such as the Register of Legal Instruments, and annotates the Certificate of Live Birth or Report of Birth.
Under the RA 9255 rules, the Affidavit of Admission of Paternity, Private Handwritten Instrument, or AUSF should be registered within 20 days from execution. If registered later, delayed registration rules may apply.
6. Wait for the annotated PSA record
After the LCRO accepts and annotates the record, the documents are endorsed to the PSA.
This is where delays often happen.
In practice, the timeline can range from a few weeks to several months depending on:
- the speed of the LCRO;
- whether the documents were complete;
- whether the PSA copy already exists;
- whether the record has discrepancies;
- whether the birth was registered abroad;
- whether the record needs manual endorsement;
- whether there are old, blurred, or inconsistent entries.
For urgent needs such as passports, school enrollment, immigration filings, or visa processing, families usually monitor both the LCRO and PSA status.
Required Documents
Requirements vary by LCRO, but these are commonly requested:
| Document | Purpose |
|---|---|
| Certified true copy of the child’s Certificate of Live Birth or Report of Birth | Shows the existing registered name and birth details |
| PSA birth certificate, if already available | Confirms what appears in the national civil registry |
| Affidavit of Admission of Paternity or acknowledgment | Proves the father expressly recognized the child |
| AUSF | Requests use of the father’s surname |
| Valid IDs of the father, mother, child of age, or guardian | Identity verification |
| Proof of authority of guardian, if applicable | Shows legal basis to act for the child |
| Supporting documents for PHI | Helps prove filiation when using a private handwritten instrument |
| Payment receipts | Filing and registration fees |
| Consular notarization or authentication documents, if abroad | Needed for documents executed outside the Philippines |
If the document was executed abroad, the family may need consular notarization or proper authentication. The DFA maintains information on document authentication through its official Apostille system, but requirements depend on whether the document is Philippine-issued, foreign-issued, notarized abroad, or executed before a Philippine Consulate.
Fees and Timelines
There is no single nationwide practical timeline because each LCRO and Consulate processes records differently. Still, these are realistic expectations.
| Item | Practical estimate |
|---|---|
| AUSF or acknowledgment notarization | Same day to a few days |
| LCRO review and registration | A few days to several weeks |
| Endorsement to PSA | Several weeks, sometimes longer |
| PSA annotation reflected in PSA copy | Often 1 to 6 months, depending on the case |
| Consular processing abroad | Depends on the specific Embassy or Consulate |
| Court process if required | Several months to more than a year |
Fees also vary by local government or consular post. For comparison, PSA publishes fees for administrative corrections under RA 9048, such as ₱1,000 for correction of clerical error and ₱3,000 for change of first name or certain RA 10172 corrections, but RA 9255 registration fees may be set locally. The PSA’s administrative correction page is available here: Administrative Petition for Correction under RA 9048, as amended.
Does Using the Father’s Surname Make the Child Legitimate?
No.
Using the father’s surname under RA 9255 does not make the child legitimate.
The child remains illegitimate unless the child later becomes legitimate through a separate legal basis, such as legitimation.
Legitimation generally applies when the parents were not legally disqualified from marrying each other at the time of the child’s conception and later validly marry. This is a different legal process from RA 9255.
RA 9255 affects the surname. It does not erase the child’s illegitimate status by itself.
Does the Father Get Custody if the Child Uses His Surname?
No.
Article 176 of the Family Code states that illegitimate children are under the parental authority of the mother.
This remains true even if:
- the father acknowledges the child;
- the child uses the father’s surname;
- the father provides support;
- the father is listed on the birth certificate;
- the father wants visitation or custody.
The Supreme Court in Grande v. Antonio recognized the mother’s parental authority over illegitimate children. A father may have rights and obligations, including support and possible visitation arrangements, but the use of his surname does not automatically transfer custody or parental authority.
Does the Father Have to Support the Child?
Yes, if filiation is established.
An illegitimate child is entitled to support under Article 176 of the Family Code. Support includes what is necessary for the child’s sustenance, dwelling, clothing, medical attendance, education, and transportation, consistent with the Family Code provisions on support.
The child’s right to support does not depend on using the father’s surname. A child may still claim support from the father even if the child continues using the mother’s surname, as long as filiation is legally established.
What If the Father Refuses to Acknowledge the Child?
If the father refuses to sign the birth certificate, affidavit, or any written acknowledgment, the administrative RA 9255 process usually cannot be completed.
The child or mother may need to establish paternity through other legal means.
Under Article 175 of the Family Code, illegitimate filiation may be established in the same way and on the same evidence as legitimate filiation. This connects to Article 172, which includes evidence such as:
- the record of birth;
- an admission of filiation in a public document;
- a private handwritten instrument signed by the parent;
- other evidence allowed by the Rules of Court and jurisprudence.
When the case is based on evidence other than the strongest written admissions, the action generally must be brought during the lifetime of the alleged parent.
In practical terms, if the father refuses voluntary acknowledgment, the issue may require a court case for paternity, support, or correction of civil registry entries.
What If the Child Was Born Before RA 9255?
This is a common issue for adults who were born before 2004 and now want to use their father’s surname.
RA 9255 took effect in 2004, but later civil registration rules expanded administrative application for many non-marital children covered by the Family Code period.
In PSA OCRG Administrative Order No. 1-2023, the Civil Registrar General amended the rules so they apply to non-marital children during the effectivity of the Family Code, including unregistered births and registered births where the child used the mother’s surname. The Supreme Court E-Library has the text of PSA OCRG Administrative Order No. 1-2023.
This matters because some older cases that previously required court action may now be processed administratively, depending on the birth date, documents, and civil registrar’s assessment.
Common Scenarios
The father signed the birth certificate, but the child uses the mother’s surname
This often happens when the child was registered under the mother’s surname even though the father acknowledged the child.
Usually, the solution is to file an AUSF with the LCRO where the birth was registered. Once accepted, the birth certificate should be annotated to show that the child shall be known by the full name using the father’s surname pursuant to RA 9255.
The father’s name appears on the birth certificate, but he did not sign
A typed father’s name is not always enough. The civil registrar may require proof that the father expressly acknowledged the child.
The father may need to execute an Affidavit of Admission of Paternity or another acceptable public document.
The father is abroad
If the father is abroad, he may execute the acknowledgment before a Philippine Embassy or Consulate, or in a form acceptable for Philippine civil registration.
Foreign notarization, apostille, or consular acknowledgment requirements depend on where the document is executed and where it will be used. Philippine Consulates often have their own RA 9255 forms and appointment procedures.
The child was born abroad
For a child born abroad to a Filipino parent, the birth is usually reported through a Report of Birth at the Philippine Embassy or Consulate.
If RA 9255 applies, the acknowledgment and AUSF may be filed with the proper Philippine Foreign Service Post. The PSA birth record or Report of Birth may later need annotation by the PSA.
The child is now an adult
An adult illegitimate child acknowledged by the father may execute the AUSF personally. The mother’s consent is not usually required because the child is already of legal age.
The adult should prepare IDs, the PSA birth certificate, the father’s acknowledgment document, and any additional documents required by the LCRO or Consulate.
The mother does not want the child to use the father’s surname
The father cannot automatically force the surname change. Since RA 9255 is permissive and the Supreme Court has treated the right as belonging to the child, the proper AUSF process and age-based consent rules matter.
For young children, the mother generally plays a key role because she has parental authority over the illegitimate child.
The child already used the father’s surname in school records, but the PSA birth certificate still shows the mother’s surname
Government agencies generally follow the PSA birth certificate. School records, baptismal certificates, medical records, or IDs may help explain usage, but they do not automatically amend the civil registry.
The family should correct or annotate the civil registry record first, then update school, passport, immigration, bank, and other records.
The family wants to remove the father’s surname later
Removing or changing a surname after it has been registered is usually more complicated than adding it through RA 9255.
If the requested change affects filiation, legitimacy, or identity, it may require a court petition under the Rules of Court, particularly Rule 103 or Rule 108, rather than a simple affidavit. RA 9048 and RA 10172 are mostly for clerical or typographical errors, certain first-name changes, and specific date-of-birth or sex corrections, not major changes that affect filiation.
RA 9255 vs. RA 9048 vs. Court Petition
People often confuse these remedies because all involve names and birth certificates.
| Remedy | Used for | Government office or court |
|---|---|---|
| RA 9255 | Allowing an acknowledged illegitimate child to use the father’s surname | LCRO, PSA, or Philippine Embassy/Consulate |
| RA 9048 | Clerical errors and certain first-name or nickname changes | LCRO, Consulate, PSA review |
| RA 10172 | Correction of day/month of birth or sex where the error is clerical | LCRO, Consulate, PSA review |
| Rule 103 | Judicial change of name | Regional Trial Court |
| Rule 108 | Cancellation or correction of civil registry entries | Regional Trial Court |
The important distinction is this: RA 9255 is not a general name-change law. It is a specific law for acknowledged illegitimate children who want to use the father’s surname.
Practical Checklist Before Filing
Before going to the LCRO or Consulate, prepare the following:
- Get the latest PSA copy of the child’s birth certificate, if available.
- Get a certified local civil registry copy from the city or municipality of birth.
- Check whether the father signed the birth certificate.
- If not, prepare the father’s Affidavit of Admission of Paternity or other acceptable acknowledgment.
- Prepare the AUSF using the required form.
- Bring valid government-issued IDs.
- If the child is 7 to 17, prepare for the child’s participation and the mother’s or guardian’s attestation.
- If the child is 18 or older, the child should personally execute the AUSF.
- If abroad, check the Philippine Embassy or Consulate requirements before notarizing documents.
- After filing, monitor the LCRO endorsement and PSA annotation.
Frequently Asked Questions
Can an illegitimate child automatically use the father’s surname in the Philippines?
No. The child may use the father’s surname only if the father has expressly recognized the child and the proper RA 9255 documents are filed.
Is the father’s signature on the birth certificate enough?
It may be enough if the signature is in the proper acknowledgment portion and the birth record is properly registered. If the child was registered under the mother’s surname, an AUSF may still be needed to use the father’s surname.
What if the father is named on the birth certificate but did not sign?
The civil registrar may require a proper acknowledgment. A typed name alone may not be enough to prove express recognition under RA 9255.
Can the father force the child to use his surname?
No. In Grande v. Antonio, the Supreme Court explained that the law is permissive. The child may use the father’s surname, but the father cannot compel it.
Does using the father’s surname give the father custody?
No. An illegitimate child remains under the parental authority of the mother under Article 176 of the Family Code, even if the child uses the father’s surname.
Can an adult illegitimate child use the father’s surname?
Yes, if the father legally acknowledged the child. An adult child may execute the AUSF personally and file it with the proper civil registry office or Philippine Foreign Service Post.
Can the child still ask for support if using the mother’s surname?
Yes. The right to support depends on established filiation, not on whether the child uses the father’s surname.
What if the father refuses to acknowledge the child?
The RA 9255 administrative route usually cannot proceed without the father’s proper acknowledgment. The child or mother may need to establish paternity through a court action.
Can a child born abroad use the Filipino father’s surname?
Yes, if RA 9255 requirements are met and the proper documents are filed with the Philippine Embassy or Consulate, or later annotated through the PSA process.
Can the child go back to the mother’s surname later?
Possibly, but it is not usually a simple affidavit process. If the surname was already officially changed or annotated, reverting to the mother’s surname may require a court petition, especially if the change affects filiation or civil status entries.
Key Takeaways
- An illegitimate child in the Philippines generally uses the mother’s surname.
- Under RA 9255, the child may use the father’s surname if the father expressly recognizes the child.
- The required document is often the Affidavit to Use the Surname of the Father, or AUSF.
- The father cannot force the child to use his surname.
- Using the father’s surname does not make the child legitimate.
- Using the father’s surname does not give the father automatic custody or parental authority.
- The mother retains parental authority over an illegitimate child under Article 176 of the Family Code.
- If the father refuses acknowledgment, a court action for paternity or filiation may be necessary.
- For children born abroad, the process usually goes through the Philippine Embassy or Consulate and later PSA annotation.
- Always align school, passport, immigration, and other records with the final PSA-annotated birth certificate.