Inheritance Rights of Legitimate vs. Illegitimate Children in the Philippines

This article explains, in practical and doctrinal terms, how Philippine succession law treats legitimate and illegitimate children—who qualifies, how to prove filiation, what each group’s “legitime” is, how to compute shares with examples, and where the hard limits and common pitfalls are. It reflects the Civil Code, the Family Code, and related statutes.

1) Core legal ideas you need first

Succession is the transfer of a decedent’s property, rights, and obligations to his/her heirs, either by law (intestate) or by will (testate). Two pillars matter here:

Compulsory heirs cannot be deprived of their legitime except for specific, serious causes of disinheritance provided by law.
Legitime is the portion of the estate that the law reserves for compulsory heirs; the free portion is what remains and can be freely disposed of.

Children—legitimate and illegitimate—are compulsory heirs. The Family Code abolished the old sub-categories of illegitimate children (e.g., “acknowledged natural,” “spurious”); today all illegitimate children stand on the same footing vis-à-vis one another, though not equal to legitimate children in every respect.

2) Who is “legitimate” and who is “illegitimate”?

Legitimate children

A child conceived or born during a valid marriage is presumed legitimate. Legitimation (see §3) can also render a child legitimate.

Illegitimate children

A child conceived and born outside a valid marriage is illegitimate, unless legitimated. The Family Code treats all illegitimate children uniformly for succession purposes.

Name and parentage notes • By statute, an illegitimate child may use the father’s surname under conditions set by law (distinct from inheritance rights). • The fact that a child carries a surname does not, by itself, settle inheritance; succession follows proof of filiation, not surnames.

3) Legitimation (upgrading status)

Legitimation occurs when parents who could have married each other at the time of conception subsequently validly marry. Legitimation retroacts to birth; the child becomes legitimate for all purposes, including succession (receiving a legitimate child’s legitime and representation rights appropriate to legitimate status).

If an impediment existed at conception that prevented the parents from lawfully marrying each other (e.g., one parent was already married to someone else), legitimation is not available.

4) Proving filiation (crucial in inheritance disputes)

Filiation may be established by:

Record evidence: birth certificate with the father’s acknowledgment; an admission of filiation in a public or private instrument.
Open and continuous possession of status as a child.
Judicial action for compulsory recognition; courts may admit DNA evidence and circumstantial proof.

Timing matters: As a rule, actions to claim filiation based on documentary acknowledgment can be brought even after a parent’s death; those based on open and continuous possession of status are generally required to be filed during the putative parent’s lifetime (nuances exist; courts examine facts closely). When in doubt, file promptly.

5) Who are the compulsory heirs (children-focused)

The Code lists as compulsory heirs, among others:

Legitimate children and descendants
Illegitimate children
Surviving spouse
Legitimate parents/ascendants (only if there are no legitimate children/descendants)

Children (legitimate or illegitimate) exclude more remote blood relatives in their lines (e.g., grandparents) from inheriting by intestacy.

6) The legitime: how big is it?

A. When only legitimate children survive

Legitime of legitimate children (collectively): ½ of the estate, divided equally among them.
Free portion: the other ½ (testator may give to anyone, subject to other compulsory heirs like a spouse, if any).

B. When only illegitimate children survive

Each illegitimate child is a compulsory heir.
Each illegitimate child’s legitime equals ½ of the share of a legitimate child in a comparable situation.
In practice (no other compulsory heirs), the estate is divided equally among illegitimate children by intestacy; in a will, their collective legitime must be respected (see examples below).

C. When legitimate and illegitimate children both survive

First reserve the legitimate children’s collective legitime = ½ of the estate (split equally among them).
Illegitimate children’s legitime: ½ of the legitime of a legitimate child, per illegitimate child, and charged against the free portion.
- If the free portion is insufficient to cover the illegitimate children’s legitimes, proportionate reduction across affected legitimes applies under the rules on inofficious dispositions.

Key memory aid: Illegitimate child = ½ of a legitimate child’s legitime. When both classes exist, start with the legitimate children’s ½-estate block, then satisfy the illegitimate children out of the free portion.

7) Representation rights (who can “step into” someone’s place)

Legitimate line: Legitimate descendants can represent a predeceased legitimate child.
Illegitimate line: Illegitimate descendants can represent their illegitimate parent in succession to that parent’s estate.
The “Iron Curtain” rule (Article 992, Civil Code): An illegitimate child cannot inherit ab intestato (by intestacy) from the legitimate relatives of his/her father or mother, and vice-versa.
- Example: An illegitimate child cannot inherit intestate from a legitimate grandparent through the parent.
- This rule does not stop inheritance from the parent him/herself; it blocks intestate succession across the legitimate–illegitimate divide in collateral/ascendant lines.

8) Interplay with the surviving spouse (quick orientation)

Children’s shares often move alongside the surviving spouse:

With legitimate children: the spouse’s legitime is equal to the share of one legitimate child (taken from the free portion).
With illegitimate children only: the spouse’s legitime is typically larger than a single illegitimate child’s (precise computation depends on headcount). These spouse rules affect how much of the free portion remains available to satisfy illegitimate children’s legitimes in mixed families.

9) Testate vs. intestate: how shares are actually computed

A. Testate succession (there is a valid will)

The will cannot impair the legitimes. The steps are:

Gross estate → deduct debts/charges → net hereditary estate.
Compute legitimes of compulsory heirs.
Whatever remains is the free portion; testamentary gifts are satisfied from here (and reduced if inofficious).

Worked example (mixed children, no spouse): Net estate = ₱12,000,000. Heirs: A and B (legitimate), X (illegitimate).

Legitimate children’s collective legitime = ½ × 12M = 6M → A = 3M, B = 3M.
A legitimate child’s legitime = 3M ⇒ Illegitimate child X’s legitime = ½ × 3M = 1.5M (from the free portion).
Free portion before X = 6M; after satisfying X’s legitime (1.5M), 4.5M remains for other testamentary dispositions.

If the will had given the entire free portion to someone else, that gift would be reduced to respect X’s ₱1.5M legitime.

B. Intestate succession (no will)

The Code supplies default shares.

Worked example 1 (legitimate only): Net estate = ₱9,000,000; heirs: 3 legitimate children → equal shares: ₱3,000,000 each.

Worked example 2 (illegitimate only): Net estate = ₱9,000,000; heirs: 2 illegitimate children → equal shares: ₱4,500,000 each.

Worked example 3 (mixed): Net estate = ₱12,000,000; heirs: A (legitimate), B (legitimate), X (illegitimate). By intestacy, the practice aligns with the legitime logic: each illegitimate child takes ½ of a legitimate child’s share.

Treat a legitimate share as “1 unit”; an illegitimate share as “½ unit.”
Total units = 1 + 1 + 0.5 = 2.5 units.
Estate ÷ 2.5 = ₱4,800,000 per unit.
- A = ₱4,800,000
- B = ₱4,800,000
- X = ₱2,400,000

(When a spouse or ascendants also concur, recalc using the Code’s unit method with their corresponding weights.)

10) Collation, donations, and reduction (when lifetime gifts distort equality)

Collation requires certain lifetime donations to compulsory heirs to be brought into the mass of the estate for computation, ensuring fair division.
If the decedent made inofficious donations (exceeding the free portion), these are reduced to restore the legitimes of legitimate and illegitimate children alike.

11) Disinheritance (when a child’s legitime can be cut)

A child—legitimate or illegitimate—may be disinherited only for causes expressly stated by law (e.g., attempt against the life of the parent, serious maltreatment, false accusation of a grave crime, etc.).

Strict compliance is required: the cause must be true, legal, and stated in the will.
If the disinheritance fails (e.g., cause unproven), the child’s legitime is restored, and voluntary heirs lose in favor of the compulsory heir.

12) The “iron curtain” in practice (pitfalls)

An illegitimate child cannot inherit by intestacy from a legitimate grandparent (or collateral legitimate relative) through the parent; the wall is between the illegitimate and the legitimate family branches.
This does not block succession from the parent (legitimate or illegitimate), nor does it bar testamentary gifts from legitimate relatives (they may give from their free portion).

13) Frequently encountered scenarios (quick answers)

Q: Can an illegitimate child inherit if the deceased left a will giving everything to someone else? A: Yes—as a compulsory heir, the child may demand reduction of inofficious dispositions to recover his/her legitime.
Q: Two sets of children: one legitimate, one illegitimate. Who gets more? A: A legitimate child gets double the share of one illegitimate child in mixed intestacy and, in testacy, an illegitimate child’s legitime is ½ of a legitimate child’s legitime.
Q: Parent acknowledged the child informally; no birth record. Is inheritance lost? A: Not necessarily. Filiation can be proved by admissions, OCPS (open and continuous possession of status), or court action—including DNA in proper cases.
Q: Child was later legitimated by parents’ marriage. What changes? A: The child becomes legitimate retroactively, with full legitimate-child shares and rights.
Q: Can illegitimate children represent their parent in claiming from a legitimate grandparent by intestacy? A: No, due to the iron curtain rule. They may, however, represent their parent in the parent’s own estate.

14) Clean computation template (use this when advising or drafting)

Ascertain heirs: list legitimate children (and their issue), illegitimate children, spouse, ascendants.
Prove filiation: collect civil registry documents, acknowledgments, and evidence.
Compute net estate: gross assets minus debts/charges.
Reserve legitimes:
- Legitimate children (collective) → ½ of estate.
- Each illegitimate child → ½ of a legitimate child’s legitime (usually from the free portion).
- Add the spouse’s legitime if any (varies by concurrence).
Apply collation/reduction for lifetime gifts that impair legitimes.
Distribute what remains (free portion) per the will; otherwise, apply the unit method for intestacy (legitimate child = 1 unit; illegitimate child = ½ unit; adjust for spouse/ascendants).
Check iron curtain before allowing intestate transfers across legitimate–illegitimate branches.

15) Practical tips

Document filiation early. Birth certificates and written acknowledgments avert litigation.
Mind prescription nuances for recognition actions—file during the putative parent’s lifetime where required.
Audit lifetime gifts; they often trigger reduction to restore legitimes.
Draft wills carefully in mixed families: expressly respect legitimes, stage gifts from the free portion, and anticipate proportionate reductions if the free portion tightens.
Flag iron-curtain risks in estate plans (e.g., if a grandparent wishes to benefit an illegitimate grandchild, use testamentary gifts or inter vivos transfers within the free portion).

Bottom line

Both legitimate and illegitimate children are compulsory heirs.
In mixed scenarios, an illegitimate child’s legitime = ½ of a legitimate child’s legitime, typically satisfied from the free portion.
The iron curtain still blocks intestate inheritance between illegitimate children and the legitimate relatives of their parents.
Good records and careful planning keep families out of court and legitimes intact.