If your child was born before you and your partner married, their PSA birth certificate likely still lists the mother’s surname and shows “illegitimate” status. Updating these records after legitimation aligns the official documents with your family’s current situation and gives your child the full legal rights of a legitimate child, including the principal use of the father’s surname.

The good news is that Philippine law provides a clear administrative path to make this happen without going to court in most straightforward cases. This guide covers exactly how the process works in practice, what documents you need, realistic timelines and costs, and how to handle common complications so you can complete the update efficiently.

What Legitimation by Subsequent Marriage Means for Your Child’s Records

Legitimation occurs when parents who had a child outside of wedlock later enter into a valid marriage, provided they were not disqualified from marrying each other at the time of the child’s conception. Once legitimated, the child’s status becomes legitimate retroactive to the date of birth.

As a legitimate child, your son or daughter is entitled to use the father’s surname principally, receive full support and succession rights, and enjoy joint parental authority. The civil registry records must be updated to reflect this through annotation rather than creating an entirely new birth certificate.

The annotation appears on the existing birth record and typically includes:

A marginal note stating that the child was legitimated by the subsequent marriage of the parents on a specific date.
The updated surname (changed to the father’s if it was previously the mother’s).
Confirmation of legitimate status.

This annotation is what appears on future PSA-certified copies. Old copies remain valid for historical reference, but current official transactions (passport, school enrollment, benefits, or inheritance matters) require the updated version showing the annotation.

Note that this is different from Republic Act No. 9255, which allows an illegitimate child to use the father’s surname upon acknowledgment but does not change the child’s status to legitimate. Legitimation goes further by updating both the surname and the legal status.

Republic Act No. 9858 further clarifies that minority of one or both parents at the time of conception is no longer a disqualifying impediment, so legitimation remains available when young parents later marry validly.

Legal Basis

The primary rules are found in the Family Code of the Philippines (Executive Order No. 209, as amended):

Article 177 (as amended by RA 9858) — Children conceived and born outside wedlock may be legitimated by the subsequent valid marriage of parents who were not disqualified by any impediment to marry each other at the time of conception (minority alone no longer counts as an impediment).
Article 178 — Legitimation takes place by subsequent valid marriage; annulment of a voidable marriage does not affect it.
Article 179 — Effects of legitimation retroact to the time of the child’s birth.
Article 174 — Legitimate children shall principally use the surname of the father.

The annotation process itself follows civil registration procedures administered by Local Civil Registry Offices (LCROs) and the Philippine Statistics Authority (PSA). The Affidavit of Legitimation is registered as a legal instrument, triggering the annotation on the child’s Certificate of Live Birth.

Step-by-Step Process to Update the Child’s Surname and PSA Records

Confirm eligibility and prepare supporting facts.
Verify that the parents had no legal impediment to marry at the time of conception (no subsisting prior marriage to someone else, no prohibited relationship). If either parent had a previous marriage, obtain proof of its dissolution (court decree or death certificate) before proceeding. If the marriage took place abroad, first ensure it is properly reported and registered in the Philippine civil registry.
Gather the required documents.
Prepare originals and photocopies. Inconsistent names or dates across documents are a common source of delay, so double-check everything.
Go to the Local Civil Registry Office where the child’s birth was originally registered.
This is usually the city or municipal hall of the place of birth. Some LCROs allow filing at the parents’ current residence (they forward the documents). Arrive early, as queues can form. Tell the staff you are there for “legitimation by subsequent marriage” or “annotation of birth certificate due to legitimation.”
Execute the Joint Affidavit of Legitimation.
Both parents sign this affidavit (templates are often available at the LCRO or Public Attorney’s Office). It states the child’s birth details, the parents’ subsequent marriage, and that there were no impediments at conception. The LCRO officer or a notary public administers the oath. If one parent is abroad, a Special Power of Attorney (notarized and apostilled) may authorize the other parent or a representative to sign.
Submit the documents and pay the fees.
The LCRO reviews everything, registers the affidavit in the Register of Legal Instruments, and prepares the annotation on the local birth record. You receive an official receipt.
LCRO annotates the record and forwards it to PSA.
The local birth register is annotated with the legitimation details and the surname change. The LCRO then transmits the annotated record to the PSA central office in Manila for updating of the national database.
Request the updated PSA birth certificate.
Once the PSA database is updated (or even while waiting, in some cases), request a new certified copy. The annotation will appear on the document, and the surname will reflect the father’s name. You can request this at any PSA outlet, through authorized partners, or via online delivery services.

Required Documents

Here is a practical checklist based on standard LCRO requirements:

Child’s Certificate of Live Birth (PSA copy or local copy from the LCRO)
Parents’ Certificate of Marriage (PSA copy preferred; local copy acceptable)
Valid government-issued IDs of both parents (passport, driver’s license, UMID, or PhilID)
Joint Affidavit of Legitimation (executed at LCRO or prepared and notarized)
CENOMAR (Certificate of No Marriage) of both parents (helpful to prove no impediments; sometimes required)
Proof of dissolution of any prior marriage, if applicable (annotated marriage certificate, court decree of nullity/annulment, or death certificate)
Special Power of Attorney and apostille (if one or both parents are abroad and cannot appear in person)
Documentary stamp tax (usually obtained at the LCRO)

Bring extra photocopies of everything. If any document was issued abroad, it generally needs an apostille from the issuing country’s competent authority plus an English translation if necessary.

Timelines, Fees, and Where to File

Timelines in practice:

LCRO processing and annotation: Same day to a few weeks (varies by office workload).
Transmission and PSA central database update: Commonly 1–3 months or longer due to volume and backlogs. Some LGUs notify clients when the annotated copy is ready for claiming.
Total time to receive an updated PSA copy: Often 2–6 months. Recent PSA “Premium Annotation Service” initiatives have sped up certain annotations to around 10 working days in participating offices, though legitimation (as a legal instrument) still frequently follows the traditional LCRO-to-PSA route.

Fees (approximate, as of 2026; confirm locally as they vary by LGU):

LCRO transaction (annotation, registration of affidavit, forms): Typically ₱200–₱500 total.
PSA certified birth certificate copy: ₱155 regular (higher with expedited or delivery options; around ₱365 via some online partners).
Notarization or apostille (if needed): ₱200–₱500+ depending on location and embassy rates.
Documentary stamp tax and miscellaneous: Small amounts.

File primarily at the LCRO of the child’s place of birth. For copies after annotation, use any PSA Serbilis center, CRS outlet, or authorized online platforms.

Special Considerations for Filipinos Abroad, OFWs, and Mixed-Nationality Cases

If you or your spouse are overseas, you can execute the Joint Affidavit of Legitimation at the nearest Philippine Embassy or Consulate (they provide notarial services and templates). Send the documents via courier or authorized representative with a properly executed and apostilled Special Power of Attorney.

Foreign marriage certificates must be apostilled and registered in the Philippines first for full effect on civil registry records.

When one parent is a foreign national, additional documents such as proof of citizenship, apostilled foreign documents, and sometimes verification of the marriage’s validity under Philippine law may be required. The LCRO will guide you on reciprocity and constitutional considerations. In these cases, processing can take longer and may benefit from early consultation with the specific LCRO or Philippine consulate.

Adult children can still have their records updated; parents typically initiate the affidavit, though the child’s involvement or consent may be requested depending on the LCRO.

Common Pitfalls and Practical Tips

Delays at the PSA central level are the most frequent frustration. Many families obtain the locally annotated birth certificate from the LCRO first and use it for urgent needs while waiting for the national database to update. Follow up politely with both the LCRO and PSA.

If a prior subsisting marriage existed at the time of conception, legitimation is not possible. PSA may reject or flag the annotation, and judicial action (such as a petition to impugn or cancel an erroneous entry) may become necessary. Always verify marital status thoroughly beforehand.

Name or date inconsistencies across documents often trigger additional requirements. Minor clerical errors can sometimes be fixed separately under RA 9048 before or alongside the legitimation filing.

If one parent is unwilling or unavailable to sign, options are limited. The LCRO may require court intervention or alternative proofs of filiation and marriage. In such cases, consulting a lawyer or the Public Attorney’s Office early saves time.

Keep digital scans and organized physical copies of every document and receipt. Track dates of submission and follow-up calls.

Frequently Asked Questions

Can I update my child’s surname to the father’s without getting married?
No. Simple acknowledgment under RA 9255 allows use of the father’s surname while the child remains illegitimate. Full legitimation and the associated surname update as a legitimate child require the subsequent valid marriage of the parents.

Do both parents have to appear in person at the LCRO?
Ideally yes. If one parent cannot appear, a properly notarized and apostilled Special Power of Attorney is usually accepted. Some LCROs are flexible; call ahead to confirm their current policy.

How long will the old PSA birth certificate remain usable?
Old copies are not invalidated but will show outdated information. For passports, school records, government benefits, or any transaction requiring current civil status, use the new annotated copy.

Is a lawyer required for this process?
No for standard cases. The process is administrative through the LCRO. However, if there are complications (prior marriage issues, disputes, or one parent unavailable), a lawyer or the Public Attorney’s Office can help prepare additional documents or file any necessary court petition.

What if my child was already using the father’s surname through RA 9255?
You can still proceed with legitimation to update the status to “legitimate” on the birth certificate. The surname may already match or will be confirmed through the annotation.

Can the process be done if the parents married abroad?
Yes, but the foreign marriage must first be reported and registered with the Philippine civil registry (usually through the DFA or the LCRO). Only then can the legitimation annotation proceed smoothly.

What appears on the updated PSA birth certificate?
The child’s surname changes to the father’s (if it was the mother’s before), the legitimacy status updates, and a clear annotation note is added citing the date of the parents’ marriage and the legal basis (subsequent marriage under the Family Code).

Is there a deadline to file for legitimation annotation?
There is no strict prescriptive period, but acting sooner avoids complications with other documents (passport validity, school records, or benefits) and makes it easier to gather supporting papers while memories and records are fresh.

Will this affect my child’s future inheritance or other rights?
Yes — positively. Legitimation gives full legitimate succession rights and removes any prior distinctions in support and parental authority.

Key Takeaways

Legitimation by subsequent marriage automatically makes your child legitimate with full rights, including the principal use of the father’s surname.
The practical update to PSA records happens through an administrative process at the LCRO using a Joint Affidavit of Legitimation, followed by annotation and transmission to the PSA central database.
Expect the complete process to take several months primarily because of the LCRO-to-PSA forwarding step; obtain the locally annotated copy when available for immediate needs.
Prepare complete, consistent documents in advance and confirm current fees and procedures directly with the specific LCRO handling the birth record.
Filipinos abroad or in mixed-nationality situations can complete the process with apostilled documents and Special Powers of Attorney, though extra time and coordination are usually required.
For most families with no complicating factors (such as prior subsisting marriages), this remains a straightforward administrative matter you can handle without court proceedings.

Once the annotation is complete and you have fresh PSA copies in hand, your child’s official records will accurately reflect your family’s current legal reality. Start by contacting the LCRO where the birth was registered — they can confirm exact local requirements and walk you through the forms on the day you file.