When a child is born to parents who aren't married, Philippine law automatically registers the child under the mother's surname unless specific legal steps are taken. Republic Act No. 9255 changes that by giving illegitimate children the right to use their father's surname instead — but only if paternity has been properly acknowledged and the correct affidavit is filed. This guide walks through exactly who can sign what, at what age, and how to get the change officially annotated on the PSA birth certificate.
This guide covers Step 1: Confirm the Father Has Legally Recognized the Child and Step 2: Understand the AUSF — the Core Document Under RA 9255, with the full details below.
- RA 9255 lets an acknowledged illegitimate child legally use the father's surname instead of the mother's
- The required document is the AUSF (Affidavit to Use the Surname of the Father) — its exact requirements depend on the child's age
- For children 0-6, the mother or guardian executes the AUSF; for ages 7-17, the child executes it with parent/guardian attestation; 18+ can execute it alone
- The father must first have expressly recognized the child, either on the birth record or through a public/private written instrument
- File the AUSF at the Local Civil Registry Office (LCRO) where the birth was recorded, and PSA will annotate the record afterward
Step 1: Confirm the Father Has Legally Recognized the Child
Before anyone can use RA 9255, the child's filiation to the father must already be established. This happens either when the father's name and signature appear on the child's birth record at the time of registration, or through a separate public document or private handwritten instrument where the father acknowledges the child as his own. Without this recognition on file, the AUSF process cannot proceed — the father would first need to execute an Affidavit of Acknowledgment/Admission of Paternity before the surname change can even be requested.
Step 2: Understand the AUSF — the Core Document Under RA 9255
The Affidavit to Use the Surname of the Father (AUSF) is the specific sworn document that formally requests the surname change. It's a short, standard form typically available at the Local Civil Registry Office (LCRO) or the National Statistics Office/PSA outlets, and it must be properly notarized before submission. Think of the AUSF as the legal 'switch' that tells the civil registry system to update how the child's surname appears going forward.
Step 3: Know Who Signs the AUSF Based on the Child's Age
The rules change depending on how old the child is at the time of filing. For a child aged 0 to 6 years old, the mother (or the guardian, if the mother is unavailable) executes the AUSF on the child's behalf. For a child aged 7 to 17 years old, the child themselves must execute the AUSF, but this must be done with the child fully understanding the consequence of the change, attested to by the mother or guardian. Once the child reaches the age of majority (18 and above), they can execute the AUSF entirely on their own, without needing anyone else's attestation.
Step 4: Prepare Supporting Documents
Typical supporting documents include the child's PSA-issued birth certificate (showing the current registered surname), a valid ID of the person executing the AUSF, and proof of the father's acknowledgment if this wasn't already recorded on the original birth certificate (such as the father's Affidavit of Acknowledgment/Admission of Paternity). If the father is deceased or unavailable to personally confirm recognition, additional supporting evidence of acknowledgment (like a notarized private handwritten instrument he signed while alive) may be required.
Step 5: File the AUSF at the Local Civil Registry Office (LCRO)
Submit the notarized AUSF and supporting documents to the LCRO of the city or municipality where the child's birth was originally registered — not necessarily where you currently live. The LCRO staff will review your documents for completeness and correctness before accepting the filing; incomplete supporting documents (especially missing proof of paternal acknowledgment) is the most common reason applications get returned for revision.
Step 6: LCRO Forwards the Annotation Request to the PSA
Once the LCRO accepts your AUSF, it coordinates with the Philippine Statistics Authority (PSA) to have the child's birth record officially annotated — meaning the original entry isn't erased, but a formal note is added and endorsed so that the child's legal surname now reflects the father's. This annotation process at the PSA level typically takes several weeks to a few months, since it goes through their central civil registration system for verification and approval.
Step 7: Request the Annotated PSA Birth Certificate
After the PSA completes the annotation, request a new copy of the birth certificate through PSAHelpline.ph or your local PSA outlet — this newly issued copy will show the annotation reflecting the AUSF and the child's updated surname. Keep several certified copies on hand, since schools, passport applications, and other government transactions will require this updated version going forward, not the original pre-annotation certificate.
Step 8: Update Other Records to Match the New Surname
Once you have the annotated PSA birth certificate, use it to update the child's school records, PhilHealth dependent records, and any other existing government or private records that still show the old surname. Doing this promptly avoids mismatched names across documents later, which can complicate school enrollment, medical benefit claims, or future passport and ID applications.
Frequently Asked Questions
The mother can execute the AUSF on behalf of a child aged 0 to 6, but this is only possible if the father has already legally recognized the child, either through the birth record itself or a separate acknowledgment document. If there's no established paternal recognition yet, the father needs to first execute an acknowledgment or admission of paternity before the mother can file the AUSF for a surname change.
Yes. For a child aged 7 to 17, the child themselves executes the AUSF, but they must do so with a full understanding of what the change means, and this understanding must be attested to by the mother or guardian. The process is still available at this age; it simply requires the child's own signature on the affidavit rather than the parent signing alone.
Yes, the law and its revised implementing rules apply retroactively to illegitimate children born before its effectivity, as long as the required acknowledgment and AUSF process are properly completed now. The specific IRR referenced in most current guidance applies to children born on or after March 19, 2004, the effectivity date of RA 9255, but earlier cases can generally still be processed under the same framework.
You file the AUSF at the Local Civil Registry Office (LCRO) of the city or municipality where the child's birth was originally registered, not necessarily your current place of residence. If you've moved to a different city since the birth was registered, you may need to coordinate with that original LCRO, sometimes through mail or an authorized representative, unless local rules allow filing through your current LCRO with forwarding.
After the LCRO accepts and forwards your AUSF, the PSA's annotation process typically takes several weeks up to a few months, since your request goes through their central verification and endorsement system before a newly annotated birth certificate can be issued. Processing times can vary depending on the PSA regional office and current caseload.
No. Without the father's express recognition of the child — either through the birth record or a separate signed acknowledgment or admission of paternity — the legal basis for using his surname under RA 9255 does not exist. If the father refuses to voluntarily acknowledge paternity, the mother may need to pursue a separate legal action (such as a filiation case in court) to establish paternity before any surname change can be processed.
Yes, and you should do this as soon as you receive the annotated PSA birth certificate. Present the updated certificate to the child's school, PhilHealth, and any other agency or institution that has records under the old surname, since mismatched names across documents can create complications later, especially for passport applications, scholarship processing, or medical benefit claims.
Conclusion
RA 9255 gives illegitimate children a clear legal path to use their father's surname, but the process hinges entirely on proper paternal acknowledgment and correctly executing the AUSF based on the child's age. Filing at the right LCRO, keeping your supporting documents complete, and promptly updating other records once the PSA annotation is done will save you from name-mismatch headaches down the road.
