In the Philippine legal system, inheritance is governed principally by Book III of the Civil Code of the Philippines (Republic Act No. 386, as amended) and is significantly affected by the provisions of the Family Code of the Philippines (Executive Order No. 209, as amended). The distinction between children from a “first family” (those born within a valid marriage) and a “second family” (those born outside a valid marriage or from subsequent relationships) arises frequently in practice due to the country’s strict monogamous marriage regime. Philippine law does not recognize absolute divorce for non-Muslim Filipinos, so subsequent unions are often void or involve extramarital relationships. Consequently, children from the first family are generally legitimate, while those from the second family are typically illegitimate, although important exceptions exist. All children, regardless of status, are entitled to certain inheritance rights as compulsory heirs, but their shares differ substantially. This article examines the complete legal landscape, including definitions, filiation, legitime, testate and intestate succession, special rules for multiple families, property regimes, and practical considerations.

I. Legal Framework

Succession law in the Philippines follows the principle of private ownership and transmission of property upon death. The Civil Code defines succession as the mode of acquiring property, rights, and obligations through the death of another (Art. 774). Inheritance may occur by will (testate) or by operation of law (intestate). The Family Code, which took effect in 1988, reformed rules on marriage, filiation, and family relations, directly impacting inheritance by determining whether a child is legitimate or illegitimate.

The Constitution (1987) and various statutes promote the equal protection of children, yet civil law maintains a distinction in inheritance shares to protect the legitimate family unit while still granting rights to acknowledged illegitimate children. Relevant supplementary laws include Republic Act No. 9255 (allowing illegitimate children to use the father’s surname upon acknowledgment) and provisions on estate taxation under the National Internal Revenue Code (as amended by the TRAIN Law), which impose a flat 6% estate tax on net estate but do not alter heir shares.

II. Classification of Children: Legitimate versus Illegitimate

Under Article 164 of the Family Code, children conceived or born during the marriage of the parents are legitimate. Legitimacy is presumed if the child is born after 180 days following the celebration of marriage and before 300 days following its termination (Art. 255, Civil Code, as supplemented by Family Code rules).

Children conceived and born outside a valid marriage are illegitimate (Art. 165, Family Code). This category includes children born to unmarried parents, from adulterous or concubinage relationships, or from void marriages. “First family” children—born to the legal spouse in a valid first marriage—are legitimate. “Second family” children—born to a subsequent partner while the first marriage subsists—are generally illegitimate.

Important exceptions apply. Article 54 of the Family Code provides that children conceived or born before the judgment of annulment or nullity of the marriage are considered legitimate. This rule covers marriages declared void due to psychological incapacity (Art. 36) and certain bigamous marriages declared void (Art. 41). In such cases, children from what appears to be a “second family” may still be classified as legitimate if conceived or born prior to the judicial declaration of nullity and if at least one parent acted in good faith.

Adopted children, whether adopted by the first or second family, are treated in all respects as legitimate children (Domestic Adoption Act and Family Code provisions).

III. Establishment of Filiation and Legitimation

Filiation must be established for inheritance rights to attach. Legitimate children enjoy a presumption of filiation proven by the record of birth, a public or private document, or other evidence (Art. 172, Family Code). Illegitimate children must prove filiation through voluntary acknowledgment or judicial action.

Modes of acknowledgment for illegitimate children (Art. 172, Family Code) include:

Record of birth in the civil registry showing the father’s name with his consent;
Admission in a public document or a private handwritten instrument by the parent;
Judicial action to claim filiation, which may be filed during the child’s lifetime or within prescribed periods.

Once acknowledged, the illegitimate child acquires full rights to support and inheritance from the acknowledging parent.

Legitimation elevates an illegitimate child to legitimate status. Under Articles 177–182 of the Family Code, legitimation occurs by the subsequent valid marriage of the parents, provided the child was conceived and born outside of wedlock and not from an incestuous or void relationship. If the impediment to the first marriage is removed (e.g., death of the first spouse or annulment), a valid second marriage can legitimate the children of that union.

IV. Compulsory Heirs and the Concept of Legitime

All children—legitimate and illegitimate—are compulsory heirs under Article 887 of the Civil Code. Compulsory heirs cannot be deprived of their legitime except by valid disinheritance for causes expressly provided by law (Art. 919).

The legitime is the portion of the net estate reserved by law for compulsory heirs and cannot be disposed of freely by will:

Legitimate children and descendants collectively receive one-half (1/2) of the net hereditary estate, divided equally among them (Art. 888).
Each illegitimate child receives one-half (1/2) of the share of one legitimate child (Art. 895).
The surviving legal spouse receives a legitime equal to that of one legitimate child when legitimate children survive, or one-fourth (1/4) of the estate in other cases.

If there are no legitimate children, illegitimate children collectively receive the full legitime that legitimate children would have received, adjusted accordingly. The remaining portion of the estate constitutes the free portion, which the testator may dispose of freely by will.

V. Inheritance Rights in Testate Succession

In testate succession, the testator may execute a will respecting the legitimes of all compulsory heirs. Legitimate children from the first family and acknowledged illegitimate children from the second family must each receive their respective legitime. The testator may distribute the free portion to favor any person, including illegitimate children or a common-law partner, but cannot impair the legitime without valid disinheritance.

Disinheritance of a child requires a will expressly stating the cause (e.g., attempt against the testator’s life, refusal to support, etc.) and must be proven.

VI. Inheritance Rights in Intestate Succession

When a person dies without a will, intestate succession applies (Arts. 960–1014, Civil Code). The order of heirs begins with legitimate children and descendants. Illegitimate children concur with legitimate children but receive half shares. The surviving legal spouse concurs with the children.

Example of share computation (assuming net estate of ₱1,000,000, no debts or other deductions):

Two legitimate children (first family) and two illegitimate children (second family):
- Legitime for legitimate children: ₱500,000 total (₱250,000 each).
- Each illegitimate child: ₱125,000 (half of ₱250,000).
- Total children’s legitime: ₱750,000.
- Surviving legal spouse (first wife): ₱250,000 (equal to one legitimate child’s share).
- Free portion: none in this intestate scenario; the entire estate is distributed according to the proportional shares.

If only illegitimate children survive, they inherit the entire estate equally. Grandchildren inherit by representation if their parent (legitimate or illegitimate) predeceased the decedent, taking the share their parent would have received, adjusted for legitimacy status.

VII. Special Rules for Children from Second Families

Children from second families are usually illegitimate and must prove filiation to claim rights. They inherit directly from the parent but receive only half the legitime of legitimate siblings. They do not inherit from the legal spouse of the first family as a matter of right, nor does the common-law partner of the second family qualify as a surviving spouse for inheritance purposes.

In cases of bigamous marriage, the second marriage is void ab initio (Art. 35 and 41, Family Code). Children conceived during the second union are illegitimate unless Article 54 applies. The first family retains priority rights to conjugal properties acquired during the valid first marriage.

Illegitimate children from the second family may still inherit from their mother’s estate on equal footing with her other children if filiation is established on the maternal side.

VIII. Role of the Surviving Spouse and Property Regimes

Only the legal spouse from the first valid marriage qualifies as a compulsory heir and surviving spouse. A partner in a second family or live-in relationship has no spousal inheritance rights. However, under Articles 147 and 148 of the Family Code, properties acquired during cohabitation may be treated as co-owned, affecting the net estate available for distribution.

The estate must first undergo liquidation of the conjugal partnership or absolute community property before distribution. Debts, funeral expenses, and support obligations to all minor children (from both families) are paid first.

IX. Practical Considerations and Challenges

Proving filiation for second-family children often requires court action, DNA evidence, or acknowledgment documents. Actions to claim filiation prescribe within periods set by the Family Code (generally during the lifetime of the parent or within years after death, depending on circumstances).

Partition of the estate among legitimate and illegitimate heirs can lead to disputes, particularly over conjugal properties or businesses. Estate administrators (often from the first family) must act impartially. Support obligations to minor children from both families continue until majority or completion of education.

Adoption by either family confers full legitimate status. Muslim Filipinos are governed by the Code of Muslim Personal Laws (Presidential Decree No. 1083), which permits polygamy and applies distinct inheritance shares (e.g., male heirs generally receiving double the share of female heirs), but the topic here focuses on the general civil law applicable to most Filipinos.

X. Relevant Special Laws and Considerations

Republic Act No. 9255 facilitates proof of filiation by allowing illegitimate children to use the father’s surname. Republic Act No. 6809 lowered the age of majority to 18, affecting capacity to inherit and receive support. Estate tax is a flat 6% on the net estate, paid before distribution.

In all cases, Philippine law balances the protection of the legitimate family with the recognition of the rights of acknowledged illegitimate children, ensuring that every child with established filiation receives a protected share of the parent’s estate. The distinction in shares reflects the legal preference for valid marriages while upholding the constitutional policy of protecting the family and all its members.