In the Philippines, the right of an illegitimate child to use their father’s surname is a matter governed by specific provisions of the Family Code and Republic Act No. 9255. For parents navigating the passport application process through the Department of Foreign Affairs (DFA), understanding these legal nuances is essential to ensure a smooth transaction.

1. The Default Rule: The Mother’s Surname

Under Article 176 of the Family Code, illegitimate children shall use the surname of their mother. This remains the default status for any child born outside of a valid marriage. If a father has not formally recognized the child, the birth certificate will reflect only the mother’s surname, and the passport must be issued accordingly.

2. Republic Act No. 9255: The Right to Use the Father’s Surname

Enacted in 2004, RA 9255 amended the Family Code to allow illegitimate children to use the surname of their father, provided that the father has formally recognized the child. This recognition can be established through:

An Admission of Paternity: Signed by the father on the back of the Certificate of Live Birth (COLB).
An Affidavit of Admission of Paternity: A separate public document or private handwritten instrument where the father admits paternity.

The AUSF (Affidavit to Use the Surname of the Father)

Even if the father recognizes the child, the child does not automatically use the surname. The mother (or the child, if of age) must execute an Affidavit to Use the Surname of the Father (AUSF). This document, filed with the Local Civil Registrar, is the legal bridge that allows the child’s name to be updated on their birth record.

3. DFA Requirements for Passport Issuance

When applying for a passport for an illegitimate child who wishes to use the father’s surname, the DFA requires specific documentation to prove the legal right to that name.

Case A: The Birth Certificate already reflects the Father’s Surname

If the Philippine Statistics Authority (PSA) birth certificate already lists the father’s surname as the child’s last name, the following are generally required:

PSA Birth Certificate: Must clearly show the father’s name and the child’s surname as the father’s.
Annotated Birth Certificate: If the name was changed after the initial registration, a PSA birth certificate with the proper annotation regarding RA 9255 is required.

Case B: The Birth Certificate shows the Mother's Surname (Updating to Father's)

If the current birth certificate reflects the mother's surname but the parents wish to use the father's surname for the passport, they must first process the RA 9255 requirements at the Local Civil Registrar. The DFA will not change a child's surname based on a father's presence or a simple request; it must be reflected on the PSA-authenticated birth certificate.

4. Special Considerations: Consent and Travel

Parental Consent: For minors, the DFA requires the personal appearance of the mother, as she holds sole parental authority over an illegitimate child under Article 176 of the Family Code.
The Father’s Presence: While the father’s surname may be used, his consent is generally not required for the passport issuance unless there is a specific legal agreement or court order stating otherwise. The mother remains the primary signatory for the application.
DSWD Clearance: If an illegitimate child is traveling abroad with someone other than the mother (even the father), a Travel Clearance from the Department of Social Welfare and Development (DSWD) is required, because the mother is the sole legal guardian by default.

5. Summary of Documentary Evidence

To ensure compliance with DFA regulations, the following documents should be prepared:

PSA Birth Certificate (with RA 9255 annotation if applicable).
Valid Government ID of the Mother (to prove identity and parental authority).
Affidavit of Support and Consent (if the mother is not accompanying the child during the application).
Original and Photocopy of the Father's ID (only if his name is being registered for the first time via an Affidavit of Admission of Paternity).

Conclusion

The evolution of Philippine law through RA 9255 has provided illegitimate children the dignity of choosing their father’s surname, provided the father grants recognition. However, for the purposes of a Philippine passport, the "paper trail" is paramount. The DFA strictly adheres to the records provided by the PSA; therefore, any desire to use the father's surname must begin with the correction or annotation of the child's birth records at the local level before a passport appointment is secured.