(Philippine legal context; general information, not legal advice.)

1) Core idea: illegitimate children are heirs, but the law limits and channels their rights

Under Philippine law, illegitimate children are recognized as compulsory heirs of their parents. That means a parent generally cannot fully cut them off from inheriting, because the law reserves for them a legitime (a mandatory minimum share), subject only to lawful disinheritance and other limited doctrines.

At the same time, Philippine succession law places two major limitations that shape outcomes:

Reduced legitime compared with legitimate children; and
The “iron curtain” rule (Civil Code Art. 992) in intestate succession, which blocks inheritance between illegitimate children and the legitimate relatives of their parents.

Understanding illegitimate children’s inheritance rights requires tying together filiation, property regime, and succession (testate vs. intestate).

2) Legal framework you must know (high level)

Key sources (non-exhaustive but foundational):

Civil Code (Book III on Succession) – rules on heirs, legitimes, intestate succession, disinheritance, representation, collation, reduction of inofficious donations, and the iron curtain (Art. 992).
Family Code – rules on legitimacy/illegitimacy, proof of filiation, and the statement that an illegitimate child’s legitime is one-half of the legitime of a legitimate child (Family Code, Art. 176, as amended).
Special laws – especially on adoption, because adoption changes inheritance status (adopted children generally inherit as legitimate children of the adopter).

3) Who is an “illegitimate child” in Philippine law?

In general, an illegitimate child is one not conceived and born in a valid marriage of the parents. Illegitimacy includes several situations, such as:

Child of parents who were not married to each other;
Child of a void marriage (subject to nuanced rules depending on circumstances);
Child born outside the father’s lawful marriage to the mother.

Why this matters: inheritance does not depend on labels alone—it depends on filiation: whether the person is legally recognized as the child of the decedent.

4) Filiation is the gateway: you inherit only if you can prove you are the decedent’s child

Inheritance rights flow from legal filiation. For illegitimate children, proving filiation is often the main battleground.

A. Common ways filiation is established

Record of birth / birth certificate (especially if the parent’s recognition appears properly);
Admission of filiation in a public document or a private handwritten instrument signed by the parent;
Open and continuous possession of the status of a child (the parent publicly treated the child as such);
Other evidence, including (in modern practice) DNA evidence, when allowed by procedural rules and jurisprudence.

B. Recognition vs. support vs. inheritance

A child may receive support or be informally acknowledged, but inheritance usually demands legally cognizable proof of filiation in estate proceedings.

C. Timing matters (actions to claim filiation)

Rules on when and how to bring actions to establish filiation can be strict. In many situations, the ability to claim depends on the kind of proof and whether the alleged parent is still alive. In estate cases, claimants often assert filiation within the settlement proceeding, but contested filiation may require a separate, properly filed action depending on the circumstances.

Practical point: if filiation is disputed, settlement can stall until the court determines who the lawful heirs are.

5) Property you can inherit: it depends on what the decedent actually owned

Illegitimate children can inherit property in the estate—not necessarily everything titled in the parent’s name.

A. If the parent was married: community/conjugal property rules come first

If the parent was married at death, many assets are part of:

Absolute Community of Property (ACP) (default for marriages after the Family Code, absent a prenuptial agreement), or
Conjugal Partnership of Gains (CPG) (more common in older marriages or under certain agreements).

Before heirs inherit:

The spouse typically gets his/her share of the community or conjugal property;
Only the decedent’s net share becomes part of the estate to be inherited.

B. The “estate” is net of debts and charges

Heirs inherit the net hereditary estate—generally what remains after:

debts, taxes, expenses of last illness/funeral, and settlement costs (subject to rules on priority and proof).

6) Two tracks of inheritance: intestate vs. testate

Inheritance looks very different depending on whether there is a valid will.

A. Intestate succession (no will, or will is ineffective)

Distribution follows the Civil Code’s intestacy rules.

B. Testate succession (there is a will)

The will controls only within limits, because the law protects legitimes of compulsory heirs (including illegitimate children).

7) The status of illegitimate children as compulsory heirs

Illegitimate children are compulsory heirs of their parents. This gives them:

A protected minimum share (legitime) in testate succession;
Standing to participate in estate settlement;
Remedies if they are omitted or their legitime is impaired.

Important nuance: being a compulsory heir does not automatically mean you inherit from all relatives—only from those the law connects you to through succession rules (and the iron curtain limits intestate links).

8) The legitime of illegitimate children (testate succession)

A. The headline rule

An illegitimate child’s legitime is one-half of the legitime of a legitimate child.

This rule becomes concrete only after identifying:

the other compulsory heirs present (legitimate children, surviving spouse, legitimate parents/ascendants, etc.), and
the applicable legitime allocations.

B. What legitime does (and does not) do

It guarantees a floor: the parent cannot will away the entire estate to others and leave the illegitimate child nothing (unless valid disinheritance applies).
It does not cap what the child may receive: the parent may still give the illegitimate child more, even the entire estate, using the free portion (and sometimes even beyond, if no other compulsory heirs are impaired).

C. Illustrative examples (simplified; assumes net estate = 12, no donations to collate/reduce)

These are teaching examples to show structure; actual computations vary with the exact family composition.

Example 1: Two legitimate children + one illegitimate child, no surviving spouse

Let each legitimate child’s legitime share be “L”.
Each illegitimate child’s legitime is “½ of L”.

A common way to conceptualize: divide the reserved portion using weights:

Legit child = 1 unit
Illegit child = 0.5 unit Total units = 1 + 1 + 0.5 = 2.5 units

Reserved portion for legitimate children is typically anchored in the Civil Code (and other compulsory heirs may affect the free portion). In practice, estate planners compute exact legitimes by applying the Civil Code’s legitime rules, then applying the “half of” rule for illegitimate children.

Example 2: One legitimate child + one illegitimate child + surviving spouse

Here, you must account for three compulsory-heir interests:

legitimate child’s legitime,
spouse’s legitime,
illegitimate child’s reduced legitime.

The take-away: once a spouse and legitimate child exist, the free portion shrinks, and the will has less room to maneuver.

If you’re studying for bar/exams: learn the legitime tables for spouse/children/ascendants first, then plug in illegitimate children as “½ share of a legitimate child.”

9) Intestate inheritance of illegitimate children from their parents

A. General right to inherit from parents

In intestacy, illegitimate children inherit from their biological/adjudicated parents, whether mother or father, once filiation is established.

B. Concurrence with legitimate children

If a decedent leaves both legitimate and illegitimate children, both sets inherit—but illegitimate children receive a reduced share relative to legitimate children (consistent with the “half of” principle).

C. Concurrence with surviving spouse

If there is a surviving spouse, the spouse’s intestate share must be applied according to the Civil Code rules, and the children’s shares adjust accordingly.

10) The “Iron Curtain Rule” (Civil Code Art. 992): the single most important limitation in intestacy

A. What the iron curtain says (in effect)

In intestate succession, an illegitimate child cannot inherit from the legitimate relatives of his/her parent, and those legitimate relatives cannot inherit from the illegitimate child, by operation of law.

This is why people call it an “iron curtain”: it cuts off intestate succession across the legitimate–illegitimate line.

B. Practical consequences

Because of Art. 992, an illegitimate child generally:

Can inherit intestate from the parent (mother/father).
Cannot inherit intestate from: the parent’s legitimate parents (grandparents), legitimate siblings, or other legitimate relatives through the parent.
Similarly, those legitimate relatives cannot inherit intestate from the illegitimate child.

C. What the iron curtain does not bar

Testamentary dispositions: A legitimate grandparent, aunt, or uncle can still leave property by will to an illegitimate relative (because Art. 992 is an intestacy rule).
Donations inter vivos: A legitimate relative can donate property during life (subject to other limits like legitimes of their own compulsory heirs).
Inheritance within the illegitimate line: Intestacy among illegitimate relatives tied through illegitimate filiation is treated differently and is not the core target of Art. 992.

Estate-planning lesson: If a family wants an illegitimate child to benefit from a legitimate relative’s property, they usually use a will or donation, not intestacy.

11) Representation: can illegitimate children “step into the shoes” of a deceased parent?

Representation is the right of a descendant to inherit in place of a parent who predeceased the decedent.

In the direct descending line, representation is generally recognized in intestacy.
But the iron curtain can block representation when the relationship to the decedent is through the parent’s legitimate line.

Example: An illegitimate grandchild trying to inherit intestate from a legitimate grandparent through the illegitimate child’s parent may be barred if the link is a legitimate-relative link covered by Art. 992.

12) Disinheritance: the only lawful way to deprive an illegitimate child of legitime

A parent may disinherit an illegitimate child only if:

There is a valid will;
The will states a lawful cause recognized by law; and
Disinheritance complies with formalities and is not void for other reasons (e.g., reconciliation).

If disinheritance is invalid, the child’s legitime is restored.

Important: Disinheritance is not the same as omission. A will that simply ignores a compulsory heir can trigger doctrines that protect compulsory heirs.

13) Omission, preterition, and impaired legitimes

A. If an illegitimate child is omitted

If a compulsory heir is completely omitted from the will, the legal consequences depend on who is omitted and the structure of the will.

Philippine succession law provides strong protections for compulsory heirs in the direct line (children/descendants), including scenarios where institution of heirs may be affected and the estate can revert to intestacy to the extent necessary to protect legitimes.

B. If gifts/will provisions impair legitime

Illegitimate children (as compulsory heirs) may file actions to:

Reduce inofficious donations (donations that exceed the donor’s free portion), and/or
Reduce testamentary dispositions that invade legitimes.

14) Collation and lifetime transfers: what if the parent already gave property during life?

Lifetime transfers matter because they can shrink the estate and/or be pulled back into the accounting.

Collation (hotchpot) is the mechanism of adding certain lifetime donations back into the mass for computing legitimes and equality among compulsory heirs (subject to technical rules and exceptions).
Even if not literally returned, values may be charged to the recipient’s share to protect other heirs’ legitimes.

Illegitimate children can invoke reduction/collation principles when their legitime is impaired, but the exact application depends heavily on:

the kind of transfer (donation, sale, simulation, advancement),
whether it is imputable to legitime or free portion, and
proof and timing.

15) What illegitimate children can inherit from: parents vs. others

A. From parents (most direct)

Intestate: yes, subject to standard rules and concurrence with other heirs.
Testate: yes, protected by legitime.

B. From legitimate relatives of parents (grandparents, legitimate siblings of parent, etc.)

Intestate: generally no, due to the iron curtain.
Testate: yes, if a will gives it to them.

C. From the other parent’s side

If filiation is established to both parents, inheritance rights exist separately from each parent’s estate (subject to each estate’s own composition and heirs).

16) Adoption and legitimation: how status can change inheritance rights

A. Legitimation (where legally available)

Legitimation generally benefits the child by elevating status (traditionally: child conceived and born outside wedlock of parents who later marry each other, provided no legal impediment existed at conception). Once legitimated, inheritance treatment aligns more closely with legitimate status.

B. Adoption

Adoption typically makes the adopted child inherit as a legitimate child of the adopter, which affects:

legitime size,
concurrence with other heirs, and
intestate rights within the adopter’s family line (a major planning consideration).

17) Procedure and remedies: how illegitimate children assert inheritance rights

Common routes:

Participation in estate settlement (testate probate or intestate settlement), asserting status as compulsory heir;
Opposing extrajudicial settlement if executed without including them (and pursuing annulment/partition remedies);
Action to establish filiation (if disputed), sometimes intertwined with estate proceedings;
Action for reduction of inofficious donations/testamentary dispositions if legitime is impaired;
Petition for partition/accounting to enforce shares.

Warning: Estate cases are evidence-heavy. Filiation disputes, simulated transfers, and title issues can turn a “simple inheritance claim” into multi-year litigation.

18) Practical guidance (Philippine reality check)

For illegitimate children (or their guardians)

Secure and preserve proof of filiation early (documents, communications, photos, school/medical records naming the parent, acknowledgment instruments).
If the parent is alive, consider proper recognition routes (where appropriate) to reduce litigation risk later.
If an estate is being settled extrajudicially without you, act quickly—delay can complicate recovery even if rights remain.

For parents who want clarity and fairness

If you want an illegitimate child to benefit from property of legitimate relatives, do not rely on intestacy—use a will or donation, mindful of legitimes of other compulsory heirs.
If you want to avoid disputes, use formal, properly executed documents and consider the property regime consequences.

19) Key takeaways

Illegitimate children are compulsory heirs of their parents.
Their protected minimum share (legitime) is smaller—generally one-half of a legitimate child’s legitime.
The iron curtain rule (Art. 992) blocks intestate inheritance between illegitimate children and the legitimate relatives of their parents.
Testamentary gifts and donations can bypass the iron curtain (subject to other heirs’ legitimes).
In practice, the biggest issues are filiation proof, property regime, and whether there is a will.

If you want, tell me a specific family setup (e.g., “decedent left a wife, 2 legitimate children, and 1 illegitimate child; estate is a house + land + bank deposits”), and I can walk through a structured share analysis and the likely dispute points under Philippine rules.