This article is for general legal information in the Philippine context and is not a substitute for advice on a specific case.

1) Why surnames become a “legal issue” in adoption

In the Philippines, a person’s surname is not merely a social label. It is a civil-status marker tied to filiation (legal parent-child relationship), legitimacy, parental authority, inheritance, and the civil registry. Because adoption restructures filiation by law, it commonly reshapes the adoptee’s legal name—especially the surname and, often, the middle name.

The legal system generally aims to (1) integrate the adoptee into the adoptive family and (2) protect privacy and stability. Those policy goals heavily influence how surnames are treated after adoption.

2) Core legal framework (Philippines)

2.1 Family Code (baseline principles)

The Family Code recognizes adoption as a mode of creating a parent-child relationship and generally leaves detailed rules to special laws. It also anchors the modern concept that filiation and civil status produce legal consequences (support, inheritance, parental authority).

2.2 Special adoption statutes (modern system)

Philippine adoption has been governed through special legislation (domestic and inter-country), and in recent years, reforms consolidated and streamlined child-care and adoption processes under an administrative framework through a specialized authority. Even when procedures evolve (court-based vs administrative), the classic substantive effects of adoption remain consistent across Philippine law:

the adoptee becomes, in law, the adopter’s child as if born to the adopter; and
the adoptee generally takes the adopter’s surname.

2.3 Civil registry rules

Because the Philippines runs on a civil registry system, the “real-world” effect of adoption on surnames is implemented through:

issuance of an Order/Decree of Adoption, and
the subsequent amendment of civil registry entries, typically resulting in an Amended Certificate of Live Birth (or its functional equivalent), with the original record protected/confidential per adoption rules.

Your surname in most official transactions ultimately tracks what appears in PSA-issued civil registry documents.

3) Substantive legal effects of adoption that drive surname outcomes

Even if your question is “about surnames,” surname rules cannot be separated from the legal effects of adoption. The most important effects are:

3.1 Legitimacy (legal status)

As a general rule in Philippine adoption law, the adoptee is considered the legitimate child of the adopter(s) for all legal intents and purposes. This matters because Philippine naming conventions are historically built around legitimacy:

Legitimate children typically carry the father’s surname and use the mother’s maiden surname as the middle name (common Philippine convention).
Illegitimate children historically used the mother’s surname and often have complications concerning the use of a middle name.

Adoption “recasts” the child into the legitimate line of the adopter(s), which is why surname and middle name rules often change together.

3.2 Transfer of parental authority

Parental authority shifts to the adopter(s). This supports a unified family identity—including name usage in school, medical matters, travel, and civil documents.

3.3 Severance of legal ties with biological parents (general rule)

Typically, adoption severs legal ties between the adoptee and the biological parents (rights and obligations), except in special scenarios recognized in adoption law (most notably where a spouse adopts the child of the other spouse—commonly called step-parent adoption—where the relationship to that spouse-parent remains).

This severance strongly influences whether continued legal use of biological parents’ surnames is allowed or discouraged.

3.4 Inheritance and support

As a legitimate child of the adopter(s), the adoptee acquires inheritance rights and support rights within the adoptive family line—again reinforcing the logic of name integration.

4) The general rule on surname after adoption

4.1 Default rule: adoptee uses the adopter’s surname

Philippine adoption law has long provided that the adoptee is entitled to use the surname of the adopter. In practical terms:

If adopted by a married couple, the adoptee normally bears the husband/father’s surname (the family surname).
If adopted by a single adopter, the adoptee generally bears the single adopter’s surname.

This is usually not treated as optional in ordinary implementation, because the civil registry amendment typically issues the adoptee a new/adapted civil identity consistent with adoptive filiation.

4.2 The legal name becomes the one on the amended civil registry record

After adoption, the adoptee’s legal name (for passports, school records, government IDs, banks, etc.) is the one shown in the amended PSA record.

Even if the child has been “known as” another surname socially (including a biological parent’s surname), official transactions commonly require consistency with PSA-issued documents.

5) What changes besides the surname: the “middle name” problem

In the Philippines, the middle name conventionally reflects the mother’s maiden surname. Adoption often changes who is legally recognized as the mother and father, so it can affect the middle name as well.

5.1 Illegitimate children and middle names (background)

A recurring legal issue is that an illegitimate child’s naming structure does not always map cleanly onto the “legitimate child format.” Philippine jurisprudence has treated the middle name as a marker of legitimate maternal lineage in the traditional naming system. This becomes important when illegitimate children are adopted and become legitimate by legal fiction.

5.2 After adoption by spouses: typical structure

Where a child is adopted by a married couple, the common resulting format is:

First Name(s): may remain the same unless changed by the adoption order
Middle Name: adoptive mother’s maiden surname
Last Name: adoptive father’s surname (family surname)

Example (illustrative):

Before: “Juan Dela Cruz”
Adopted by: Pedro Santos and Maria Reyes
After: “Juan Reyes Santos”

5.3 After adoption by a single adopter: the middle name may be unclear in practice

If the adopter is single, the law’s effect (“legitimate child of adopter”) is clear, but Philippine naming convention expects both a paternal surname and maternal maiden surname.

Two realities follow:

The surname generally becomes the adopter’s surname.
The middle name may require careful handling and may depend on what the adoption order specifies and how civil registry authorities implement naming in that scenario.

A key Supreme Court ruling often cited in this space is In re: Adoption of Stephanie Nathy Astorga Garcia (2005), which is widely discussed for how it treats middle names and the inadmissibility of using a biological father’s surname as a middle name after adoption in that context. The Court’s reasoning is tied to how middle names function within Philippine naming traditions and legitimacy constructs.

6) Can the adoptee keep using the biological parents’ surname after adoption?

This is the center of your topic. The short legal reality is:

Officially (legally), adoption typically replaces the adoptee’s surname with the adopter’s surname.
Continued official use of a biological parent’s surname is usually inconsistent with the legal fiction of adoptive filiation, unless a lawful mechanism specifically permits it (or the case is structured such that the “biological surname” is also the adoptive surname).

But the details matter. Below are the most common scenarios.

7) Scenarios and how biological surnames can (or cannot) appear

Scenario A: “Standard” adoption by non-biological adopters (most common integration model)

Result: The adoptee generally takes the adopter(s)’ surname. The biological parents’ surnames ordinarily drop out of the adoptee’s legal name.

Can the adoptee still use the biological surname?

Socially/informally: A person may still be known by a former surname within a community, but this can cause mismatches and complications.
Legally/officially: Using a different surname in official records generally requires a legal basis (e.g., a lawful change-of-name process) and must be consistent with civil registry documentation.

Why the law leans this way: Adoption is designed to create a stable legal identity aligned with the adoptive family’s filiation and responsibilities.

Scenario B: Step-parent adoption (spouse adopts the child of the other spouse)

This is a major exception area because the child already has a biological parent who remains in the picture and is married to the adopter.

Effect on filiation: The child becomes the legitimate child of the adopter and the spouse-parent, and legal ties to the other biological parent (if any) may be severed.

Effect on surname:

If the child already bears the surname of the spouse-parent and that surname aligns with the new family surname, there may be no practical surname change.
If the child bears the surname of the spouse-parent but the family surname differs (e.g., the child uses the mother’s surname, and the stepfather adopts), adoption commonly results in the child taking the stepfather’s surname, aligning with legitimacy conventions.

Biological surname use after step-parent adoption:

If the “biological surname” is that of the spouse-parent who remains a parent, the name may remain or be integrated (because it is not “biological vs adoptive”—it is part of the continuing legal parent line).
If the biological surname is tied to the parent whose legal ties are severed, continued official use becomes much harder to justify in the adoption framework.

Scenario C: Adoption by a biological parent (or within the biological family line)

Sometimes a biological parent adopts their own child (e.g., to legitimize status in a specific legal context, or due to procedural history), or a relative adopts.

Surname outcomes vary:

If the child already uses the adopting parent’s surname (or the adopting parent’s family surname), the change may be minimal.
If the adopting relative has a different surname, the adoptee generally takes the adopter’s surname.

Using the other biological parent’s surname:

Philippine jurisprudence (notably the Stephanie case) is commonly invoked to reject inserting the biological father’s surname as a middle name after adoption in that situation, because the middle name conventionally signals maternal lineage and legitimacy-based naming structure.

Scenario D: Adult adoption

Adult adoption exists in Philippine practice, but name change consequences can be especially sensitive because the adoptee may have an established professional identity.

General tendency: Even for adult adoptees, the legal effect of adoption points toward bearing the adopter’s surname as a legitimate child—unless the order and implementing rules explicitly handle naming differently.

Practical reality: If an adult wants to retain a biological surname for professional or identity reasons, this typically must be addressed explicitly in the legal process (and/or via a separate lawful change-of-name mechanism). Otherwise, the amended civil registry record tends to control.

Scenario E: Inter-country adoption and foreign naming outcomes

When adoption is completed under inter-country mechanisms, the adoptee’s name may be changed or structured under the adoptive country’s legal system.

For Philippine records, the crucial point is that Philippine documentation and civil registry recognition processes aim for an identity consistent with lawful adoption outcomes, but implementation can involve coordination (recognition/recording) and documentation steps that may affect how the name is reflected in Philippine-issued documents later.

8) Biological parents’ surname as the adoptee’s middle name: what Philippine law tends to allow or disallow

This is where many disputes arise: even if the adoptee must take the adopter’s surname, can the adoptee keep a biological parent’s surname as a middle name?

8.1 The policy tension

Identity argument: Keeping a biological surname preserves heritage and continuity.
Adoption integration argument: Adoption aims to place the child fully within the adoptive family line, and the traditional middle-name convention points to maternal lineage within legitimacy structures.

8.2 The Stephanie ruling and its practical effect

The Supreme Court decision in In re: Adoption of Stephanie Nathy Astorga Garcia (2005) is frequently discussed for rejecting the use of the biological father’s surname as the adoptee’s middle name after adoption in that setting. While facts matter, the common doctrinal takeaway is:

In the Philippine naming system, the middle name is not a free-floating “extra surname,” and courts are cautious about using it to retain a paternal biological surname when adoption has reconfigured filiation.

8.3 What this means on the ground

Courts/authorities often treat the adoptee’s middle name (where used) as tied to the adoptive mother’s maiden surname—not the biological father’s surname—after adoption by spouses, and similarly aligned to adoptive lineage principles in other contexts.

9) How the civil registry implements the name change

9.1 Amended birth record

After the adoption order becomes final/executory and is properly endorsed for civil registry action:

The local civil registrar and PSA processes typically produce an amended record reflecting the adoptive parent(s) as the child’s parent(s) and reflecting the adoptee’s name consistent with the adoption order and governing rules.

9.2 Confidentiality and sealing

Adoption systems in the Philippines impose confidentiality to protect the child and the adoptive family. Common features include:

restricted access to adoption records, and
controlled release of original birth information.

This confidentiality policy is one reason the legal system often resists continued official use of biological-parent surnames as part of the adoptee’s legal identity—because it can defeat privacy protections and the “clean break” principle in standard adoptions.

10) If the adoptee wants to use a biological parent’s surname anyway: lawful pathways (and friction points)

10.1 Distinguish “social use” from “legal name”

Social use: a person may be known by another surname informally, but this can create documentary problems.
Legal use: official use generally must follow the PSA record, unless changed by lawful means.

10.2 Possible legal mechanisms (general)

Depending on facts, an adoptee seeking to retain or restore a biological surname typically confronts one of these approaches:

Address it within the adoption proceedings/order If allowed under procedural rules, the desired legal name should be specified and justified early—because the amended civil registry record will flow from the adoption order.
Separate change-of-name process Philippine procedure recognizes court processes for change of name (and administrative correction for limited clerical matters). A true change of surname that contradicts an adoption-based civil record is not usually a “simple correction”—it often requires a formal legal basis and compelling justification.
After rescission (where available) If adoption is rescinded under the rules (traditionally, rescission is a remedy primarily for the adoptee under Philippine adoption law), legal consequences can include reversion of civil status and restoration of prior civil registry entries, which can restore use of the biological surname as a legal identity marker. This is a drastic remedy and not merely a naming tool.

10.3 Common obstacles

Best interests and stability: authorities emphasize stability of identity and family integration.
Civil registry consistency: government systems are document-driven; mismatches raise red flags.
Jurisprudential constraints: particularly around middle names and the meaning they carry in Philippine naming conventions.

11) Rescission/termination and what happens to the surname

Philippine adoption law traditionally provides that adoption is meant to be stable and not easily undone. Where rescission is allowed (commonly at the instance of the adoptee under specified grounds):

Effects often include:

restoration of parental authority to biological parents (if appropriate/available),
cancellation or modification of amended civil registry entries, and
potential reversion to the adoptee’s original surname as reflected in restored records—subject to the terms of the rescission and civil registry implementation.

Name effects can become complex if the adoptee has used the adoptive surname for many years in school and professional life.

12) Related Philippine laws that people confuse with adoption surname rules

12.1 Illegitimate child using the father’s surname (acknowledgment route)

Philippine law allows, under certain conditions, an illegitimate child to use the biological father’s surname when paternity is recognized/acknowledged. This is not adoption—it is a rule about filiation and naming for illegitimate children.

This matters because families sometimes consider adoption when what they actually want is a surname change reflecting paternal acknowledgment, or vice versa.

12.2 Rectification of simulated birth records

Philippine law also provides a pathway to correct “simulated birth” situations (where a child was registered as if born to persons who are not the biological parents). That framework can involve administrative processes and adoption-like legal effects, including legitimizing the child’s status within the caregiving family and regularizing the child’s name in the civil registry.

13) Practical consequences (real-life paperwork) after surname changes through adoption

Once adoption changes the adoptee’s legal surname, expect knock-on effects:

School records: updating school forms, diplomas, and transcripts
Medical records: aligning patient identity and guardianship
Travel: passports and travel consent documents must match PSA records
Government IDs: PhilSys/SSS/GSIS/Pag-IBIG/PhilHealth (as applicable)
Banking and insurance: KYC identity verification is strict
Property and succession: correct legal identity is crucial for inheritance and titles

Because of these, the “practical” system strongly pressures use of the adoptive surname once adoption is finalized and recorded.

14) Key takeaways on surname and biological surname use

General rule: after adoption, the adoptee is treated as the adopter’s legitimate child and is entitled (and typically expected) to use the adopter’s surname as the adoptee’s legal surname.
Civil registry controls: the adoptee’s legal name is what appears in the amended PSA civil registry record produced from the adoption order.
Biological surnames usually drop out of the legal name in standard adoptions because legal ties are generally severed and policy favors integration and confidentiality.
Step-parent adoption is the biggest “exception zone” in practice because one biological parent remains legally in the picture and family surname alignment may already exist.
Middle name disputes are real: Philippine jurisprudence (notably the Stephanie adoption case) is often invoked to restrict using the biological father’s surname as a middle name after adoption in that context, reflecting the legal meaning attached to middle names in Philippine naming tradition.
Keeping a biological surname officially after adoption usually requires a specific lawful basis (handled in the adoption order if permitted, or through a separate legal name-change mechanism), and will be assessed against stability, best interests, civil registry consistency, and confidentiality policies.