Below is a broad overview of the inheritance rights of illegitimate children under Philippine law. This discussion is meant for general informational purposes only and should not be construed as legal advice. If you need guidance on a specific situation, you should consult a licensed attorney in the Philippines.

1. Definition of Illegitimate Children

Under Philippine law—specifically the Family Code (Executive Order No. 209, as amended)—an illegitimate child is one born to parents who are not legally married at the time of the child’s conception or birth, or whose marriage is void from the beginning. Illegitimate children are distinct from:

Legitimate children: Born or conceived during a valid marriage.
Legitimated children: Born out of wedlock but later legitimated by the subsequent valid marriage of the child’s parents under certain conditions.
Adopted children: Acquired legal filiation through the process of adoption.

Despite being categorized differently, illegitimate children are recognized as having rights to support, inheritance, and other privileges as explicitly provided by law—though these rights differ in some ways from those of legitimate children.

2. Legal Basis: Family Code and Civil Code

2.1. Family Code Provisions

Article 175 of the Family Code states that illegitimate children may establish their illegitimate filiation (i.e., prove that a certain individual is their father or mother) by any of the recognized methods under the law:
- Record of birth appearing in the civil register or a final judgment.
- An admission of filiation in a public document or a private handwritten instrument signed by the parent concerned.
- Any other means allowed by the Rules of Court and special laws (e.g., DNA testing, open and continuous possession of the status of an illegitimate child).
Article 176 (as originally worded) and its later amendment by R.A. No. 9255 focus on parental authority and surname usage. This does not directly alter inheritance shares, but clarifies how an illegitimate child may use the surname of the father. Nonetheless, establishing and recognizing paternity is crucial for inheritance rights to take effect.

2.2. Civil Code Provisions

Article 887 of the Civil Code lists the compulsory (or “forced”) heirs. Illegitimate children are included among the forced heirs of their parents, meaning they are entitled to a “legitime”—a portion of the estate that the deceased is not free to distribute away because it is reserved by law for compulsory heirs.
Article 895 and subsequent articles govern the specific manner of distributing the legitime among compulsory heirs, including illegitimate children.
Article 988 and onward explain how descendants, ascendants, and illegitimate children share in the estate when there is no will (intestate succession). These provisions must be read together with the Family Code to determine the proper shares of legitimate versus illegitimate children.

3. Rights to Inheritance

3.1. General Rule: Entitlement to a Legitime

Illegitimate children are compulsory heirs (also called forced heirs) in the estate of their biological parent. This means:

They cannot be deprived of their legitime, except in certain extraordinary circumstances (e.g., valid disinheritance under the grounds specified in the Civil Code).
They are entitled to receive a portion of the estate even if the parent leaves a will (testate succession) attempting to bequeath assets exclusively to others.

3.2. Share of Illegitimate Children

Under Philippine law, the legitime of an illegitimate child is generally one-half (1/2) the legitime of a legitimate child. In other words, for every portion a legitimate child receives, an illegitimate child receives half that amount.

Example: Suppose a deceased parent leaves behind two legitimate children and one illegitimate child, and the net estate for distribution of the legitimes is PHP 3,000,000 (for illustration). If each legitimate child’s legitime is PHP 1,000,000, then the illegitimate child’s share would be PHP 500,000.

Additionally, illegitimate children share equally amongst themselves the portion allocated to illegitimate children under the law. If there are multiple illegitimate children, each one gets an equal share of that “illegitimate children’s portion.”

3.3. Proof of Filiation

To claim inheritance, the illegitimate child must prove filiation—that is, prove the child is indeed that of the deceased. The accepted modes of proof include:

Birth certificate or recognition in the civil registry.
Notarized or handwritten instrument (e.g., affidavit) where the parent acknowledges the child.
Judicial action: A court judgment establishing paternity.
Other means allowed by law: This can include DNA testing or the presentation of witnesses and documentary evidence showing open and continuous acknowledgment by the parent.

If filiation cannot be established, the child may not successfully claim inheritance.

4. Distinction from Legitimated Children

A child born out of wedlock can become legitimated if the parents subsequently enter into a valid marriage, provided there was no legal impediment for them to marry at the time of the child’s conception. Once legitimated, the child’s inheritance rights become the same as those of a legitimate child (i.e., the “half share” rule no longer applies to them).

However, if the marriage that could “legitimate” the child is not valid (due to legal impediments, lack of capacity, etc.), the child remains illegitimate. The process and conditions for legitimation are governed by Articles 177 to 182 of the Family Code.

5. Inheritance by Will (Testate Succession)

Even if a parent executes a will, the law protects the legitime of illegitimate children by classifying them as forced heirs. The testator (the parent making the will) must preserve the forced heir’s legitime. Any testamentary disposition that deprives or reduces an illegitimate child’s legitime below the statutory amount can be contested in court.

While testators can freely bequeath the free portion (anything in excess of the total legitimes of compulsory heirs) to any beneficiary, they cannot bypass an illegitimate child’s right to at least half the share of a legitimate child.

6. Disinheritance

The Civil Code enumerates grounds under which a child (legitimate or illegitimate) may be validly disinherited, such as when the child commits serious wrongdoing against the parent (e.g., an attempt on the parent’s life). However, the grounds for disinheritance are strictly construed and must be proven. Absent these valid grounds, an illegitimate child—being a forced heir—may not be deprived of the legitime.

7. Practical Considerations and Procedural Aspects

Timing: An action to claim inheritance is typically filed upon the death of the parent. If the parent dies intestate (without a will), inheritance is governed by the rules on intestate succession, including the forced heir rules for illegitimate children.
Recognition Cases: If the child’s filiation or paternity/maternity is disputed, the child (or a legal representative) may file a petition for recognition in court. DNA evidence is becoming more common and is often accepted by Philippine courts if properly presented and subjected to the usual rules of evidence.
Proof of Heirship: When estate settlement or administration proceedings begin, all heirs—legitimate, illegitimate, or otherwise—must establish their right to inherit.
Legal Representation: Particularly when there is controversy or when the child has not been formally acknowledged, seeking counsel from a lawyer is critical to navigate the complexities of establishing filiation and distributing the estate properly.

8. Key Takeaways

Illegitimate children are forced heirs and thus have inheritance rights under Philippine law.
Their legitime is half that of a legitimate child’s share.
Recognition of paternity or maternity is essential; without proof of filiation, an illegitimate child cannot claim inheritance.
In testate succession, the legitime of illegitimate children is reserved by law, and it cannot be willed away.
Only valid disinheritance under the Civil Code may bar an illegitimate child from receiving the legitime.
Legitimation (through a subsequent valid marriage of the parents) transforms illegitimate children into legitimate children for inheritance purposes.
Procedural actions to prove filiation or claim an inheritance share often involve court proceedings, and professional legal advice is advisable.

Disclaimer

This article is intended only to provide general information on the subject matter, drawn from the Family Code and the Civil Code of the Philippines, as well as relevant statutes and jurisprudence. It is not a substitute for personalized legal advice from a qualified lawyer who can assess specific facts and provide tailored guidance. If you have questions about your situation or need to initiate legal proceedings, you should consult an attorney licensed to practice in the Philippines.