I. Introduction

In Philippine civil law, the surname of a child is not merely a matter of personal identity. It reflects rules on filiation, parental authority, succession, civil status, and documentary registration. One recurring issue is whether an illegitimate child may use the surname of the father.

The controlling rule is that an illegitimate child generally uses the surname of the mother. However, under specific conditions, an illegitimate child may use the surname of the father. This exception is recognized under Republic Act No. 9255, which amended Article 176 of the Family Code, and is implemented through civil registry rules issued by the Philippine Statistics Authority, formerly the National Statistics Office.

The right is not automatic in every case. It depends on whether the child’s filiation to the father has been legally established, usually through the father’s recognition or acknowledgment.

II. Basic Rule Under Article 176 of the Family Code

Article 176 of the Family Code originally provided that illegitimate children shall use the surname of the mother. They are under the parental authority of the mother and are entitled to support in conformity with the Family Code. Their legitime is one-half of the legitime of a legitimate child.

Republic Act No. 9255 amended Article 176 by allowing an illegitimate child to use the surname of the father if the child’s filiation has been expressly recognized by the father through any of the means allowed by law.

Thus, the present rule may be summarized as follows:

An illegitimate child shall generally use the surname of the mother, but may use the surname of the father if the father has expressly recognized the child in accordance with law.

III. Meaning of “Illegitimate Child”

An illegitimate child is a child conceived and born outside a valid marriage, unless the law classifies the child as legitimate or legitimated.

Examples include:

A child born to parents who were never married;
A child born from a void marriage, subject to certain exceptions;
A child born from an adulterous or concubinage relationship;
A child born from parents who could not legally marry each other at the time of conception or birth.

The classification matters because the law treats legitimate and illegitimate children differently in matters such as surname, parental authority, support, and succession.

IV. The General Rule: The Child Uses the Mother’s Surname

The default rule is maternal surname use.

This is because, in illegitimate filiation, maternity is usually established by the fact of birth, while paternity requires recognition or proof. The mother’s relationship to the child is apparent from the birth itself, but the father’s legal relationship must be established according to law.

Therefore, when an illegitimate child is registered and the father does not recognize the child, the child is registered using the mother’s surname.

V. Exception: Use of the Father’s Surname Under Republic Act No. 9255

Republic Act No. 9255 permits an illegitimate child to use the father’s surname when the father has expressly recognized the child.

This law does not convert the child into a legitimate child. It also does not give the father automatic parental authority. It merely allows the use of the father’s surname once legal recognition of paternity exists.

The child remains illegitimate unless legitimated by subsequent valid marriage of the parents, where legitimation is legally available.

VI. Legal Basis for Recognition by the Father

For the illegitimate child to use the father’s surname, the father must have recognized or acknowledged the child through legally acceptable means.

Recognition may be made through:

The record of birth appearing in the civil register;
A final judgment;
An admission of illegitimate filiation in a public document;
An admission of illegitimate filiation in a private handwritten instrument signed by the father.

These modes are consistent with the rules on proving illegitimate filiation under the Family Code.

VII. Recognition in the Birth Certificate

The most common way is through the birth certificate.

If the father appears in the child’s birth certificate and signs the appropriate portion acknowledging paternity, the child may use the father’s surname pursuant to Republic Act No. 9255 and its implementing rules.

The father’s name appearing on the birth certificate is not always enough by itself if there is no proper acknowledgment. The civil registrar usually requires the father’s signature or another legally sufficient document showing recognition.

VIII. Recognition Through an Affidavit of Admission of Paternity

Another common method is through an Affidavit of Admission of Paternity.

This is a sworn statement where the father expressly admits that he is the father of the child. It may be executed at the time of registration or after the birth has already been registered.

If the affidavit is properly executed, it may be used as basis for allowing the child to use the father’s surname.

IX. Recognition Through a Private Handwritten Instrument

The law also recognizes admission of paternity in a private handwritten instrument signed by the father.

Examples may include a handwritten letter, note, or statement where the father clearly admits that the child is his.

For this to be legally useful, the document must clearly show acknowledgment of paternity. It must also be signed by the father. Because private documents are more susceptible to dispute, the civil registrar or court may require proper authentication or additional proof.

X. Recognition Through a Public Document

A public document may also serve as proof of acknowledgment.

Examples include:

A notarized affidavit of acknowledgment;
A notarized agreement where the father admits paternity;
A public instrument where the child is expressly recognized as the father’s child.

A public document has stronger evidentiary value than an ordinary private writing because notarization converts it into a public document and gives it evidentiary weight.

XI. Recognition Through Final Judgment

A court judgment may also establish filiation.

This may happen when the child, the mother, or a proper representative files an action to establish illegitimate filiation, and the court finds sufficient evidence that the alleged father is indeed the father.

After finality of judgment, the child may use the father’s surname if the judgment establishes paternity in a manner sufficient under the law.

XII. The Affidavit to Use the Surname of the Father

Aside from proof of paternity, civil registry rules require an Affidavit to Use the Surname of the Father, commonly referred to as the AUSF.

The AUSF is the document used to implement Republic Act No. 9255 in the civil registry. It indicates that the child will use the surname of the father.

Depending on the child’s age and circumstances, the AUSF may be executed by:

The father;
The mother;
The child, if of legal age;
The guardian, in appropriate cases.

The requirements may vary depending on whether the child is a minor, whether the father is alive, whether the father acknowledged paternity in the birth certificate, and whether the acknowledgment was made in a separate document.

XIII. If the Child Is Still a Minor

If the child is a minor, the AUSF is usually executed by the mother or guardian, with the required proof of the father’s acknowledgment.

The reason is that the child does not yet have full legal capacity to execute legal documents independently.

Where the father himself acknowledges paternity and consents to the use of his surname, the process is simpler. If the father’s acknowledgment is absent or defective, court action may be necessary.

XIV. If the Child Is Already of Legal Age

If the child is already of legal age, the child generally has the right to decide whether to use the father’s surname, provided filiation has been legally recognized.

An adult illegitimate child cannot ordinarily be compelled to use the father’s surname. The use of the father’s surname is a right or privilege granted by law, not an absolute obligation imposed on the child.

XV. Is the Use of the Father’s Surname Mandatory?

No.

Republic Act No. 9255 allows the illegitimate child to use the surname of the father. It does not command that the child must use the father’s surname.

The wording of the law is permissive. Therefore, even if the father recognizes the child, the child may continue using the mother’s surname, especially if the child is already of age and prefers to retain the existing surname.

XVI. Does Use of the Father’s Surname Make the Child Legitimate?

No.

The use of the father’s surname does not change the child’s civil status.

An illegitimate child who uses the father’s surname remains illegitimate unless the child is legitimated under the law. Legitimation is a separate legal concept that generally requires that the parents were not disqualified from marrying each other at the time of conception and later validly marry.

Using the father’s surname affects the child’s registered name, but it does not erase illegitimacy.

XVII. Does It Give the Father Parental Authority?

No, not by itself.

Under Article 176 of the Family Code, an illegitimate child is generally under the parental authority of the mother. This remains true even if the child uses the father’s surname.

The father may have obligations such as support, and he may have visitation rights where appropriate, but parental authority over an illegitimate child generally belongs to the mother.

The use of the father’s surname does not automatically transfer custody or parental authority to the father.

XVIII. Does It Affect Support?

The father’s recognition of the child is significant because it may support the child’s right to demand support.

An illegitimate child is entitled to support from both parents. If the father has acknowledged the child, it becomes easier to establish the basis for claiming support.

However, use of the father’s surname is not the source of the right to support. The source is filiation. The surname is merely a consequence that may follow once filiation is acknowledged or proven.

XIX. Does It Affect Succession Rights?

The use of the father’s surname does not itself create inheritance rights. Succession rights arise from filiation.

An illegitimate child who has established filiation to the father is entitled to inherit from the father as a compulsory heir, subject to the limits provided by the Civil Code and Family Code.

The legitime of an illegitimate child is generally one-half of the legitime of a legitimate child. However, the actual computation depends on the number and classes of heirs.

Thus, the important point is not merely whether the child uses the father’s surname, but whether the child’s filiation to the father is legally established.

XX. Does It Affect the Birth Certificate?

Yes.

If the child was originally registered using the mother’s surname, and later qualifies to use the father’s surname, the civil registry record may be annotated.

The original birth record is generally not erased. Instead, an annotation is made reflecting the child’s use of the father’s surname pursuant to Republic Act No. 9255.

The civil registry process is administrative if the requirements are complete. If there is a dispute, defect, or absence of recognition, a court proceeding may be necessary.

XXI. Administrative Process Before the Civil Registrar

The process usually involves filing documents with the Local Civil Registrar where the child’s birth was registered.

Typical documents include:

Certified true copy of the child’s Certificate of Live Birth;
Affidavit to Use the Surname of the Father;
Affidavit of Admission of Paternity, if separate from the birth certificate;
Valid identification documents of the parties;
Proof of acknowledgment, such as a public document or private handwritten instrument;
Other documents required by the Local Civil Registrar or the Philippine Statistics Authority.

After evaluation, the civil registrar may annotate the birth record and transmit the annotated record to the Philippine Statistics Authority.

XXII. If the Father Signed the Birth Certificate

If the father signed the birth certificate acknowledging paternity, this is usually the clearest administrative route.

The child may be allowed to use the father’s surname upon compliance with the AUSF requirements and civil registry procedures.

The father’s signature indicates express recognition. Without such signature, the mere entry of the father’s name may be questioned, especially if the entry was supplied by someone else.

XXIII. If the Father Did Not Sign the Birth Certificate

If the father did not sign the birth certificate, the child may still use the father’s surname if there is another legally sufficient acknowledgment.

This may include:

A notarized affidavit of admission of paternity;
A private handwritten instrument signed by the father;
A final court judgment establishing filiation.

If none exists, the civil registrar generally cannot simply allow use of the father’s surname based on the mother’s declaration alone.

XXIV. If the Father Is Deceased

If the father is deceased, the child may still establish filiation using documents executed by the father during his lifetime, such as:

A signed birth certificate;
A notarized acknowledgment;
A private handwritten admission;
Other competent evidence in a court action.

However, if there is no written acknowledgment, proving filiation may require judicial action and must comply with the prescriptive periods under the Family Code.

XXV. If the Father Refuses to Acknowledge the Child

If the father refuses to acknowledge the child, the child cannot simply adopt the father’s surname through an administrative application.

The remedy is usually an action to establish illegitimate filiation. The court may consider evidence such as:

Written admissions;
DNA evidence, where admissible and relevant;
Consistent treatment of the child as his own;
Family records;
Testimony and surrounding circumstances.

However, under the Family Code, the strongest and most direct forms of proof remain those expressly recognized by law, especially written acknowledgment and final judgment.

XXVI. DNA Evidence

DNA evidence may be relevant in actions involving paternity. Philippine jurisprudence recognizes the value of DNA testing in appropriate cases, especially where paternity is disputed.

However, DNA evidence by itself does not automatically amend a civil registry entry. It must usually be presented in a proper proceeding, and the court must make a ruling.

In short, DNA evidence may help prove paternity, but administrative use of the father’s surname still generally requires recognized legal documentation or a court judgment.

XXVII. Important Case Law: Grande v. Antonio

In Grande v. Antonio, the Supreme Court discussed the effect of Republic Act No. 9255. The Court emphasized that the law gives an illegitimate child the right to use the father’s surname when the father has expressly recognized the child.

The case also confirms that the use of the father’s surname is permissive, not mandatory. The child is allowed, but not compelled, to use the father’s surname.

This is important because the law protects the child’s identity and welfare. It does not give the father unilateral power to impose his surname on the child.

XXVIII. Important Case Law: De Jesus v. Estate of Dizon

In cases involving illegitimate filiation, the Supreme Court has repeatedly emphasized the importance of the modes of proving filiation under the Family Code.

An illegitimate child may prove filiation through the record of birth, final judgment, written admission in a public document, or written admission in a private handwritten instrument signed by the parent.

Where these are absent, the law allows other evidence only under specific circumstances and within the required periods.

XXIX. Important Case Law: Tijing v. Court of Appeals

In Tijing v. Court of Appeals, the Supreme Court recognized DNA testing and physical resemblance as relevant in resolving questions involving a child’s identity and parentage.

While not solely about Republic Act No. 9255, the case is significant because it reflects the Court’s willingness to consider scientific evidence in parentage disputes.

XXX. Prescriptive Periods in Establishing Illegitimate Filiation

The period for bringing an action to establish illegitimate filiation depends on the evidence available.

If the action is based on the child’s record of birth, final judgment, or written admission in a public document or private handwritten instrument signed by the father, the action may generally be brought during the lifetime of the child.

If the action is based on other evidence, it must generally be brought during the lifetime of the alleged parent.

This distinction is critical. A child who has strong written proof of acknowledgment has a more secure position than one relying only on testimonial or circumstantial evidence.

XXXI. Effect on Middle Name

In Philippine naming practice, the middle name often reflects the mother’s surname. For legitimate children, the usual format is:

Given Name + Mother’s Surname as Middle Name + Father’s Surname as Last Name

For illegitimate children using the father’s surname under Republic Act No. 9255, the child may similarly carry the mother’s surname as middle name and the father’s surname as last name, subject to civil registry rules.

However, implementation depends on the PSA and Local Civil Registrar’s guidelines. The key point is that the use of the father’s surname under RA 9255 typically results in the father’s surname becoming the child’s last name.

XXXII. Child’s Name Before and After RA 9255

Before Republic Act No. 9255, an illegitimate child generally had to use the mother’s surname even if the father acknowledged the child.

After Republic Act No. 9255, acknowledgment by the father can allow the child to use the father’s surname.

For example:

Before RA 9255: Juan Santos, where Santos is the mother’s surname.

After RA 9255, with proper acknowledgment: Juan Santos Reyes, where Santos is the mother’s surname and Reyes is the father’s surname.

XXXIII. Children Born Before RA 9255

Republic Act No. 9255 may apply to children born before its effectivity, provided the requirements are satisfied.

The law was intended to benefit illegitimate children whose fathers have acknowledged them. Thus, even a person born before the law may seek annotation of the birth record to use the father’s surname, subject to civil registry procedures.

XXXIV. Can the Mother Object?

The mother’s role is important, especially if the child is a minor. Since the mother has parental authority over an illegitimate child, her participation is usually required in administrative processes involving a minor child.

However, if the child is already of legal age and filiation to the father is legally established, the adult child’s own decision becomes central.

Where there is conflict between parents, the welfare and rights of the child are controlling.

XXXV. Can the Father Force the Child to Use His Surname?

No.

The father cannot unilaterally compel the child to use his surname.

Recognition gives the child the option to use the father’s surname. It does not give the father ownership over the child’s name or identity.

The right belongs to the child, not to the father.

XXXVI. Can the Child Later Stop Using the Father’s Surname?

This depends on the circumstances.

If the child’s civil registry record has already been annotated and official documents have been changed, reverting to the mother’s surname may require a separate legal or administrative process.

If the change affects official civil registry entries, the person may need to follow procedures under civil registry laws or, in some cases, file a petition in court.

The answer may vary depending on whether the desired change is merely a correction, a cancellation of annotation, or a substantial change of name.

XXXVII. Distinction Between Use of Father’s Surname and Change of Name

Use of the father’s surname under RA 9255 is not the same as an ordinary change of name.

A change of name is generally governed by Rule 103 of the Rules of Court or by administrative correction laws where applicable.

RA 9255 is a special law allowing an illegitimate child to use the father’s surname upon recognition. It operates through annotation of the civil registry record, not necessarily through a full judicial change-of-name proceeding.

However, if the requested alteration goes beyond what RA 9255 permits, judicial proceedings may be required.

XXXVIII. Distinction Between Correction of Entry and Change of Surname

A clerical or typographical error in a birth certificate may sometimes be corrected administratively.

But changing the child’s surname from the mother’s surname to the father’s surname is not merely a clerical correction. It involves filiation and civil status implications.

Therefore, the civil registrar must require compliance with RA 9255 and its implementing rules.

XXXIX. If the Child Was Registered as Legitimate by Mistake

Sometimes a child born outside marriage is mistakenly registered as legitimate, with the father’s surname.

This is a serious issue because legitimacy affects civil status. Corrections involving legitimacy or illegitimacy are substantial and usually require judicial proceedings.

Administrative correction is generally not enough where the change affects status, filiation, or legitimacy.

XL. If the Parents Later Marry

If the parents later validly marry, the child may be legitimated if the legal requirements for legitimation are present.

Legitimation generally requires that the child was conceived and born outside wedlock to parents who, at the time of conception, were not disqualified by any legal impediment to marry each other, and who subsequently validly marry.

Once legitimated, the child becomes legitimate for legal purposes. The surname issue is then governed by the rules applicable to legitimate children.

XLI. If the Father Is Married to Someone Else

A father who is married to another person may still acknowledge an illegitimate child.

The child may use the father’s surname if the requirements of RA 9255 are complied with.

However, the child remains illegitimate. The acknowledgment does not affect the father’s existing marriage, does not make the child legitimate, and does not give the mother rights as spouse.

The child may still be entitled to support and inheritance rights as an illegitimate child.

XLII. If the Mother Is Married to Someone Else

This is more legally complex.

A child born to a married woman may be presumed legitimate with respect to her husband, depending on the circumstances and timing under the Family Code.

If the law presumes the child to be legitimate, the issue is not simply one of allowing the biological father’s surname. The presumption of legitimacy must first be addressed through proper legal proceedings.

In such cases, the civil registrar cannot casually substitute the alleged biological father’s surname. Questions involving legitimacy, paternity, and impugning legitimacy are substantial matters usually requiring court action.

XLIII. If the Father Is a Foreigner

An illegitimate Filipino child may use the foreign father’s surname if paternity is legally acknowledged and civil registry requirements are met.

There may be additional documentary requirements if the acknowledgment was executed abroad, such as consular authentication, apostille, translation, or compliance with foreign-document rules.

The child’s citizenship is a separate issue. Use of the father’s surname does not automatically determine citizenship.

XLIV. If the Child Was Born Abroad

If the child was born abroad to a Filipino parent and the birth was reported to the Philippine consulate, the Report of Birth may reflect the child’s surname according to Philippine rules.

If the child is illegitimate and seeks to use the father’s surname, proof of acknowledgment and compliance with RA 9255 may still be required.

The process may involve the Philippine embassy or consulate, the Department of Foreign Affairs, the Local Civil Registrar, and the PSA, depending on the status of registration.

XLV. Effect on Passports, School Records, and Government IDs

Once the birth certificate is annotated and the PSA record reflects the authorized use of the father’s surname, the child may use the updated civil registry record to update:

Passport records;
School records;
PhilHealth, SSS, GSIS, or Pag-IBIG records;
Bank records;
Tax records;
Employment records;
Other government-issued IDs.

Most institutions require a PSA-issued annotated birth certificate before changing records.

XLVI. Role of the Philippine Statistics Authority

The Philippine Statistics Authority maintains civil registry records at the national level.

Even if the Local Civil Registrar annotates the record, the PSA copy must also reflect the annotation for the change to be widely accepted.

In practice, many institutions rely on the PSA-issued birth certificate rather than only the Local Civil Registrar copy.

XLVII. Role of the Local Civil Registrar

The Local Civil Registrar is the first office usually approached for implementation of RA 9255.

The LCR evaluates the documents, determines whether the father’s acknowledgment is sufficient for administrative processing, and records the annotation.

If the LCR finds the documents insufficient, the applicant may be required to submit additional proof or seek judicial relief.

XLVIII. Court Action When Administrative Remedy Is Insufficient

Court action may be necessary when:

The father refuses to acknowledge the child;
The father is deceased and there is no clear written acknowledgment;
The birth record contains conflicting entries;
The child’s legitimacy is disputed;
The change affects civil status;
The civil registrar denies administrative processing;
There is a need to establish filiation by judgment.

The proper action may vary depending on the issue: establishment of filiation, correction or cancellation of entry, change of name, or settlement of estate.

XLIX. Evidence Commonly Used to Prove Paternity

Evidence may include:

Birth certificate signed by the father;
Affidavit of acknowledgment;
Letters or written communications from the father;
Financial support records;
School or medical records identifying the father;
Photographs and family records;
Testimony of relatives or witnesses;
DNA evidence;
Public documents naming the child as the father’s child;
Prior judicial or administrative admissions.

The sufficiency of evidence depends on the nature of the proceeding and the mode of proof required by law.

L. The Child’s Best Interest

Although surname rules are technical, courts and administrative agencies are guided by the welfare of the child.

The child’s name affects identity, dignity, social recognition, and legal documentation. The law aims to balance:

The child’s right to identity;
The mother’s parental authority;
The father’s recognition of paternity;
The integrity of civil registry records;
The prevention of fraudulent or unsupported claims of filiation.

LI. Common Misconceptions

1. “If the father’s name is written on the birth certificate, the child can automatically use his surname.”

Not always. The father must have validly acknowledged the child. A mere entry may not be enough if not supported by the father’s signature or other legally sufficient recognition.

2. “Using the father’s surname makes the child legitimate.”

No. The child remains illegitimate unless legitimated under the law.

3. “The father gets custody if the child uses his surname.”

No. Parental authority over an illegitimate child generally remains with the mother.

4. “The mother can name any man as the father and use his surname.”

No. The alleged father’s recognition or a court judgment is required.

5. “RA 9255 is a change-of-name law.”

Not exactly. It is a special law allowing an acknowledged illegitimate child to use the father’s surname.

6. “The child has no inheritance rights unless he uses the father’s surname.”

Wrong. Inheritance rights depend on filiation, not surname.

7. “The father can force the child to carry his surname.”

No. The law allows the child to use the surname; it does not give the father unilateral control.

LII. Practical Scenarios

Scenario 1: Father signed the birth certificate

The child may generally use the father’s surname by filing the required AUSF and supporting documents with the Local Civil Registrar.

Scenario 2: Father did not sign but later executed a notarized acknowledgment

The child may use the father’s surname upon submission of the acknowledgment and AUSF, subject to the registrar’s evaluation.

Scenario 3: Father refuses to acknowledge the child

The child cannot administratively use the father’s surname. A court action to establish filiation may be required.

Scenario 4: Father is deceased but left a handwritten letter admitting paternity

The child may rely on the handwritten admission, subject to proof of authenticity and compliance with civil registry or court requirements.

Scenario 5: Child is already an adult and wants to use the father’s surname

The adult child may execute the required documents, provided filiation has been legally recognized.

Scenario 6: Mother wants the child to use the father’s surname, but father never acknowledged the child

The mother’s desire alone is insufficient. The father’s acknowledgment or a court judgment is needed.

Scenario 7: Father acknowledged the child but the child prefers the mother’s surname

The child may continue using the mother’s surname. Use of the father’s surname is permissive.

LIII. Relationship With Support Proceedings

In a support case, proof of paternity is essential. If the father has acknowledged the child, that acknowledgment may be used to support the claim.

However, a support case and an RA 9255 surname application are distinct. One concerns financial obligation; the other concerns use of surname and civil registry annotation.

The same proof of filiation may be relevant to both.

LIV. Relationship With Estate Proceedings

In estate proceedings, an illegitimate child claiming inheritance must prove filiation.

Use of the father’s surname may support the child’s claim, but it is not conclusive by itself. The court will examine whether filiation was legally established.

If the father recognized the child in a public document, birth record, or private handwritten instrument, the child has a stronger basis to claim inheritance.

LV. Relationship With Adoption

Adoption is different from acknowledgment.

If a child is adopted, the child’s surname may change based on the adoption decree and amended birth record. Adoption creates a legal parent-child relationship between the adopter and adoptee.

RA 9255, by contrast, concerns the biological father’s acknowledgment of an illegitimate child and the child’s use of the biological father’s surname.

LVI. Relationship With Legitimation

Legitimation is also different.

Legitimation changes the child’s status from illegitimate to legitimate when legal requirements are met. RA 9255 does not change status; it only permits surname use.

If a child is later legitimated, civil registry entries may be updated to reflect legitimation, and the child’s surname follows the rules for legitimate children.

LVII. Procedural Checklist

A typical RA 9255 application may require the following steps:

Secure a PSA or Local Civil Registrar copy of the child’s birth certificate.
Determine whether the father acknowledged paternity in the birth certificate.
If not, secure a valid acknowledgment document.
Prepare the Affidavit to Use the Surname of the Father.
Submit valid IDs and supporting documents.
File with the Local Civil Registrar where the birth was registered.
Pay applicable fees.
Wait for annotation and transmission to the PSA.
Secure the annotated PSA birth certificate.
Use the annotated birth certificate to update other records.

LVIII. Limits of the Civil Registrar’s Authority

The civil registrar performs administrative functions. The registrar cannot decide complex questions of paternity, legitimacy, fraud, or conflicting claims in the same way a court can.

If the documents clearly satisfy the law, the registrar may annotate the record. If the documents raise substantial legal questions, the applicant may be directed to court.

LIX. Importance of Accurate Civil Registry Entries

Civil registry records enjoy legal significance. They are used in passports, school enrollment, employment, marriage, succession, immigration, and court proceedings.

Because of this, the law does not allow casual or unsupported changes to a child’s surname. Recognition by the father must be legally shown.

LX. Rights of the Illegitimate Child

An illegitimate child has the right to:

Bear the mother’s surname as a default rule;
Use the father’s surname if legally recognized under RA 9255;
Receive support from parents;
Inherit as a compulsory heir, subject to law;
Establish filiation through the means allowed by law;
Maintain personal identity and dignity;
Be protected according to the child’s best interests.

LXI. Duties of the Father Upon Recognition

Recognition of an illegitimate child is not merely symbolic. It may carry legal consequences, including:

Obligation to support the child;
Recognition of the child’s successional rights;
Possible participation in matters affecting the child, subject to the mother’s parental authority and the child’s welfare;
Legal acknowledgment of filiation.

However, recognition does not automatically give the father custody or parental authority superior to the mother.

LXII. Duties and Rights of the Mother

The mother of an illegitimate child generally has parental authority. She has the right and duty to care for the child, make decisions for the child’s welfare, and represent the child in many legal matters while the child is a minor.

In surname matters, the mother’s participation is usually necessary when the child is a minor, especially in the execution of documents and submission to the civil registrar.

LXIII. The Child’s Autonomy Upon Majority

Once the child reaches majority age, the child’s personal decision becomes more important.

An adult child may choose whether to use the father’s surname if legally entitled. The father’s acknowledgment does not erase the adult child’s autonomy over identity.

LXIV. Legal Effect of RA 9255 in One Sentence

Republic Act No. 9255 gives an illegitimate child whose filiation has been expressly recognized by the father the right, but not the obligation, to use the father’s surname, without changing the child’s status as illegitimate and without transferring parental authority from the mother to the father.

LXV. Conclusion

The Philippine rule on the use of the father’s surname by an illegitimate child is a balance between identity, filiation, parental authority, and civil registry integrity.

The default rule is that an illegitimate child uses the mother’s surname. The exception, introduced by Republic Act No. 9255, allows the child to use the father’s surname when the father has expressly recognized the child through legally acceptable means.

This recognition may appear in the birth certificate, a public document, a private handwritten instrument signed by the father, or a final judgment. Once the requirements are met, the child’s civil registry record may be annotated through the proper process.

The use of the father’s surname does not make the child legitimate, does not give the father automatic parental authority, and does not itself create inheritance or support rights. Those rights flow from filiation, not from the surname. The right to use the father’s surname belongs primarily to the child and is permissive, not compulsory.