Below is a comprehensive discussion of the legitimation process for an illegitimate child in the Philippines who already bears the father’s surname. This is based on Philippine law and prevailing administrative regulations. Please note that this discussion is for general informational purposes only and does not constitute legal advice. For specific concerns, it is best to consult a qualified attorney.

1. Overview of Illegitimacy and Legitimation

Definition of Illegitimate Child
Under the Family Code of the Philippines (Executive Order No. 209), an illegitimate child is one born outside a valid marriage. Such a child carries certain legal consequences, including not being entitled to the same status and rights as a legitimate child unless the child is subsequently legitimated.
What Is Legitimation?
Legitimation is a legal remedy by which an illegitimate child’s status is elevated to that of a legitimate child. Under Articles 177 to 182 of the Family Code, legitimation occurs by the subsequent valid marriage of the parents, provided there existed no legal impediment for them to marry each other at the time the child was conceived.
Effect of Legitimation
Once legitimated, the child is deemed legitimate from the time of birth, effectively conferring all rights of a legitimate child (e.g., full inheritance rights, use of the father’s surname, and so forth).

2. Use of Father’s Surname vs. Legitimation

Use of Father’s Surname (Republic Act No. 9255)
Republic Act (R.A.) No. 9255 (also known as the “Revilla Law”) amended Article 176 of the Family Code. It allows an illegitimate child, upon the father’s recognition or acknowledgement, to use the father’s surname.
- If the father acknowledges the child through a public document (e.g., Affidavit of Acknowledgment / Admission of Paternity) or through the appropriate registration forms at the Local Civil Registrar (LCR), the child can be registered under the father’s surname—even though the child’s status remains “illegitimate” until a proper legitimation occurs.
Legitimation vs. Use of Surname
- Using the father’s surname (R.A. 9255) is primarily a matter of civil registration and recognition but does not automatically convert the child’s status from illegitimate to legitimate.
- Legitimation requires a valid subsequent marriage of the child’s parents, or a legal process (in very narrow circumstances) that changes the child’s civil status from illegitimate to legitimate.

Hence, it is possible for an illegitimate child to already bear the father’s surname but still not be considered legitimate. If the parents marry later and fulfill the requirements for legitimation, the child’s status changes to legitimate retroactively.

3. Requirements for Legitimation

In order for legitimation to be valid in the Philippines, all of the following must be satisfied:

No Legal Impediment to Marry at the Time of Conception
The parents must have been free to contract marriage (i.e., neither was legally disqualified or barred from marrying) at the time the child was conceived.
- For instance, if at the time of conception the mother was still married to someone else (and not lawfully separated or widowed), there would be a legal impediment to marry. In such a scenario, legitimation normally cannot proceed, since the child could be considered adulterous or incestuous, both of which are not subject to legitimation.
Subsequent Valid Marriage of Parents
The parents must contract a valid marriage after the birth of the child. This marriage removes the condition that caused the child’s illegitimacy, effectively “legitimating” the child.
Registration of Legitimation with the Local Civil Registrar
- After the parents marry, they must file an Application for Legitimation (often called an “Affidavit of Legitimation” or “Joint Affidavit of Legitimation”) with the Local Civil Registrar where the child’s birth was registered.
- Additional supporting documents (e.g., Marriage Certificate, Birth Certificate, Affidavits, valid IDs of parents) must be submitted.
- The Local Civil Registrar annotates the child’s birth record to reflect the new status as “legitimate.”
Child Not Disqualified for Legitimation
The child must not have been conceived out of relationships considered void or illegal in such a way that bars legitimation under the law, such as incestuous relations or bigamous marriages.

4. Step-by-Step Process of Legitimation

Although the administrative details can vary slightly by local government unit, here is the general sequence:

Parents Marry
- The parents solemnize their marriage in accordance with Philippine law. A valid Marriage Certificate is then issued.
Prepare Necessary Documents
Gather the required documents for legitimation registration. Commonly required:
- Certified True Copy of the child’s Birth Certificate
- Certified True Copy of the Marriage Certificate of the parents
- Joint Affidavit of Legitimation or Affidavit of Legitimation signed by both parents (some local civil registries may provide a standard form)
- Valid IDs of both parents
- Other supporting documents as the Local Civil Registrar may require
File Application with the Local Civil Registrar
- Proceed to the Local Civil Registrar (LCR) of the city or municipality where the child’s birth was originally registered.
- Submit the documents and pay the corresponding fees.
- The registrar will process the application and annotate the child’s birth certificate.
Verification and Annotation by the Philippine Statistics Authority (PSA)
- After the LCR completes the annotation, the updated record is transmitted to the PSA.
- You can request a copy of the child’s newly annotated Birth Certificate from the PSA (usually after a certain waiting period, often several weeks or months). The new birth record should show that the child is now “legitimate” by virtue of legitimation.
Effects of Legitimation
- Once processed, the child’s status is officially changed to “legitimate” from the time of birth, with all rights and privileges granted by law.

5. Key Points When the Child Already Bears the Father’s Surname

Even if the child already uses the father’s surname (by virtue of R.A. 9255):

Status Remains “Illegitimate” Until Completion of Legitimation
Using the father’s surname does not by itself convert the child’s status to “legitimate.” The child is simply recognized as the father’s child and has the surname for civil registry and identification purposes.
Subsequent Marriage Is Crucial
If the parents later marry and satisfy all the legal conditions, the child can be legitimated. Once legitimated, the child will retain the father’s surname and be recognized as a legitimate child from birth.
Annotation of Birth Certificate
Post-legitimation, the Local Civil Registrar and the PSA will annotate the birth record. This annotation is the formal public record that the child is now legitimate.

6. Special or Exceptional Cases

Judicial Recognition
In rare instances where a child’s legitimation is contested or complicated by unusual factual or legal issues (e.g., an alleged impediment to marry is being challenged), court intervention may be necessary. A court proceeding can clarify paternity, rule on the existence or non-existence of impediments, and uphold or deny the legitimation.
Foreign Marriages
If the parents married abroad, the marriage certificate must be registered with the Philippine Consulate or the Philippine Embassy in the country where the marriage took place. A certified copy or Report of Marriage must then be forwarded to the PSA. This document is used during the legitimation process.
Timing and Late Registration
Ideally, the legitimation documents are filed soon after marriage. However, if the parents neglected to file for legitimation for several years, it is still possible to do so later—though late registration may require additional requirements or fees from the LCR.
Adoption vs. Legitimation
Adoption is a separate process entirely and does not apply when both biological parents can marry and legitimize the child. Adoption involves different procedures, typically requiring a judicial proceeding if you are adopting a child to whom you are not already legally married or recognized as the biological parent.

7. Practical Reminders

Legitimation Is Retroactive
Once legitimated, the child is considered legitimate from birth. Thus, the child’s inheritance rights and legal status are the same as though born within wedlock.
Legitimation Is Generally Administrative
As long as there is no controversy regarding paternity, capacity to marry, or authenticity of documents, legitimation usually proceeds via an administrative process at the Local Civil Registrar.
Keep Certified/Original Copies
Parents should keep certified copies of all documents (marriage certificate, birth certificate, affidavits, etc.) because these will be needed for future transactions (e.g., passport application, school enrolment, etc.).
Consult a Professional
For situations involving legal impediments, disputes over paternity, or complications in registering marriages performed abroad, it is wise to consult an attorney or seek assistance from the Local Civil Registrar or the Philippine Statistics Authority’s legal department for guidance.

8. Conclusion

Legitimation under Philippine law elevates an illegitimate child’s status to that of a legitimate child, but it requires a valid subsequent marriage between parents who had no legal impediment at the child’s conception.
The child’s prior use of the father’s surname under R.A. 9255 does not automatically grant legitimacy; it merely acknowledges paternity and confers the right to use the father’s surname.
To change the child’s civil status to legitimate, the parents must undergo the legitimation process, which is typically filed with the Local Civil Registrar where the child’s birth was recorded.
Once completed, legitimation takes effect retroactively to the child’s birth, granting the child all rights of a legitimate child in the eyes of Philippine law.

If you believe you qualify for legitimation, or if you need to clarify any special circumstances (e.g., doubts about paternity, foreign marriage documentation, or contested impediments), consult a legal professional or visit your Local Civil Registrar for personalized guidance.