1) Core idea: illegitimate children are compulsory heirs of their parent

Under Philippine succession law, an illegitimate child (as a matter of status/filiation) is a compulsory heir of their biological parent. Being a compulsory heir means the child has a legally protected minimum share (legitime) that cannot be taken away by will or donations, except through a valid disinheritance under the Civil Code.

This article focuses on succession to the decedent’s exclusive property—property that belongs to the decedent alone and forms part of the decedent’s net hereditary estate after debts, expenses, and (if applicable) liquidation of the marital property regime.

2) What counts as “exclusive property” and why it matters

A. Exclusive property under Philippine family/property regimes

If the decedent was married, the estate you distribute is not “everything the couple owned.” You first determine what portion belongs to the decedent.

Typical exclusive property includes (general guide consistent with the Family Code regimes):

Property owned by the decedent before marriage
Property acquired during marriage by gratuitous title (donation/inheritance), unless the donor/testator provided otherwise
Property for the decedent’s personal and exclusive use (with important exceptions)
Property acquired with exclusive funds (subject to tracing rules)

B. Sequence matters: liquidation before succession

When there is a surviving spouse and a marriage property regime applies (absolute community or conjugal partnership):

Liquidate the community/conjugal property
Determine the decedent’s share in that regime (this becomes part of the decedent’s estate)
Add the decedent’s exclusive properties
Subtract obligations (debts, taxes/expenses chargeable to the estate, etc.)
What remains is the net hereditary estate to be divided among heirs

Even when the topic is “exclusive property,” in real cases you must still do this accounting because the surviving spouse has two different kinds of rights:

Property right (their half/share in the community/conjugal assets), and
Successional right (their inheritance share as an heir)

3) Establishing illegitimate status (filiation): no filiation, no inheritance

An “illegitimate child” in succession is not about labels—it is about legally provable filiation.

A. How filiation is typically proven

Common proofs include:

Record of birth (birth certificate) showing the parent
Acknowledgment by the parent (public/private documents where legally sufficient)
Open and continuous possession of the status of a child (factual recognition, support, use of surname in appropriate circumstances, etc.)
Judicial declaration of filiation (a court action when contested)

B. Practical succession consequence

If filiation is undisputed, the child participates as heir.
If contested, succession often pauses on that issue: the child may need to establish filiation in court to inherit.

4) The illegitimate child’s protected minimum: legitime

A. Basic rule

An illegitimate child’s legitime is one-half (1/2) of the legitime of a legitimate child.

This “half-share” principle appears across both:

Testate succession (with a will), and
Intestate succession (no will)

B. Why “legitime” is the pivot point

In wills, the decedent may distribute the free portion (the part not reserved as legitime). But the law forces a minimum distribution to compulsory heirs, including illegitimate children.

If the will or lifetime gifts infringe the legitime:

The remedy is typically reduction (bringing gifts/allocations down to lawful levels), not automatically voiding everything.

5) Intestate succession: who inherits exclusive property when there is no will?

When there is no will, the Civil Code’s intestacy rules control. The presence of children—legitimate or illegitimate—generally pushes other relatives out of the line.

A. If the decedent leaves illegitimate children only (no legitimate children)

Illegitimate children inherit the entire net hereditary estate (the decedent’s exclusive property plus any decedent’s share in community/conjugal assets after liquidation), subject to the rights of a surviving spouse if any (see below).

B. If the decedent leaves illegitimate children and a surviving spouse (but no legitimate children)

A special intestacy rule applies:

The surviving spouse gets 1/3
The illegitimate children, collectively, get 2/3 (divided among them)

This is not computed by the usual “child equals spouse” rule; it is a distinct statutory allocation.

C. If the decedent leaves legitimate children and illegitimate children

In intestacy, the usual ratio is:

Each legitimate child gets a full share
Each illegitimate child gets half of a legitimate child’s share

A common way to compute:

Assign “weights”: legitimate child = 1; illegitimate child = 0.5
Divide the estate in proportion to weights Example (no spouse): 2 legitimate, 2 illegitimate Total weight = 2(1) + 2(0.5) = 3 Each legitimate = 1/3; each illegitimate = 1/6

D. If the decedent leaves legitimate children, illegitimate children, and a surviving spouse

As a general intestacy pattern:

The spouse shares like a legitimate child in that line-up
Illegitimate children remain at half of a legitimate child’s share

A common computation method (unless a special rule applies):

weights: legitimate child = 1; spouse = 1; illegitimate child = 0.5 Example: spouse + 1 legitimate + 2 illegitimate Total weight = 1 (spouse) + 1 (legitimate) + 2(0.5) = 3 Spouse = 1/3; legitimate = 1/3; each illegitimate = 1/6

E. Do the decedent’s parents inherit if the decedent leaves illegitimate children?

As a general principle in intestacy, descendants exclude ascendants. So if the decedent is survived by children (including illegitimate children of the decedent), the decedent’s parents typically do not inherit by intestacy from that decedent.

6) Testate succession: what if there is a will disposing of exclusive property?

A will can distribute property, but it cannot legally “ignore” compulsory heirs without consequence.

A. If a will gives the illegitimate child less than the legitime

The disposition is inofficious to the extent it impairs legitimes.
The law provides reduction so that compulsory heirs receive their minimum shares.

B. If a will omits an illegitimate child entirely

If the omitted child is a compulsory heir in the direct line and there is preterition (complete omission), the effect can be severe:

Institutions of heirs may be annulled to protect compulsory heirs (the technical effect depends on the will’s structure and whether the omission is complete and in the direct line).
Specific devises/legacies may survive insofar as they are not inofficious.

Because this is highly structure-dependent, preterition issues are typically analyzed by:

Identifying compulsory heirs,
Checking whether omission is complete,
Determining what portions of the will must yield to legitimes.

C. Freedom is mostly in the “free portion”

A testator has broad control only over the portion that remains after all legitimes are satisfied. If the estate is small relative to compulsory heirs, the will’s “choices” can shrink dramatically.

7) The “iron curtain rule”: the biggest limitation unique to illegitimacy

A major Philippine doctrine in intestacy is the barrier between legitimate and illegitimate familial lines (commonly called the “iron curtain rule” under the Civil Code).

A. What it blocks

As a general rule in intestate succession:

An illegitimate child cannot inherit ab intestato from the legitimate relatives of their parent (e.g., legitimate grandparents, legitimate siblings of the parent), and
Those legitimate relatives cannot inherit ab intestato from the illegitimate child through that line

B. What it does not block

The illegitimate child can inherit from the parent (this article’s main topic).
The illegitimate child can inherit from other persons who validly name them in a will (testate succession), subject to legitime rules of that testator.
Relationships among illegitimate children sharing the same parent are generally treated under the intestacy rules applicable to siblings, but the “iron curtain” specifically targets crossing between legitimate and illegitimate lines.

8) Collation, donations, and “exclusive property” that was given away before death

Because illegitimate children are compulsory heirs, lifetime transfers involving exclusive property can be challenged if they undermine legitimes.

A. Donations that impair legitimes

If the decedent donated exclusive property during life and the estate left at death is insufficient to satisfy legitimes, heirs can seek:

Reduction of inofficious donations (the excess beyond what the law allows)

B. Collation (bringing advances into account)

Collation rules are technical and depend on:

The type of heir,
The kind of transfer,
Whether it is treated as an advance on inheritance In practice, estate settlement often requires an accounting of significant lifetime transfers to determine whether any heir effectively received an advance that must be equalized or reduced.

9) Disinheritance: can an illegitimate child be cut off?

Yes—but only through valid disinheritance:

It must be for a cause specifically allowed by law (Civil Code enumerations),
It must be made in a will, typically expressly stating the cause, and
The cause must be true and provable (and can be contested)

If disinheritance fails, the child’s right to legitime is restored.

10) Common distribution scenarios for exclusive property (worked examples)

Assume the amounts below represent the net hereditary estate attributable to the decedent (exclusive property plus decedent’s share in marital property after liquidation, minus obligations).

Scenario 1: No spouse; 3 illegitimate children; no legitimate children

Illegitimate children inherit the entire estate, divided equally Each gets 1/3.

Scenario 2: With spouse; 3 illegitimate children; no legitimate children

Spouse = 1/3
Illegitimate children collectively = 2/3 Each child = (2/3) ÷ 3 = 2/9.

Scenario 3: No spouse; 2 legitimate children and 2 illegitimate children

Weights: L=1 each; I=0.5 each Total weight = 2 + 1 = 3 Each legitimate = 1/3 Each illegitimate = 1/6.

Scenario 4: With spouse; 2 legitimate children and 2 illegitimate children

Weights: spouse=1; each legitimate=1; each illegitimate=0.5 Total weight = 1 + 2 + 1 = 4 Spouse = 1/4 Each legitimate = 1/4 Each illegitimate = 1/8.

11) Procedure in practice: settlement, titles, and partition

A. Typical steps

Identify heirs and prove filiation (and marital status)
Inventory assets and classify: exclusive vs community/conjugal
Liquidate marital property regime (if any)
Pay estate obligations (debts, administration expenses, taxes as applicable)
Compute legitimes (if testate) or apply intestacy rules (if no will)
Partition and transfer titles (judicial or extrajudicial, depending on circumstances)

B. Practical friction points involving illegitimate children

Disputes on filiation/recognition
Heirs concealing exclusive property or prior donations
Wills that omit compulsory heirs
Confusion between the spouse’s property share (from liquidation) and inheritance share (from succession)

12) Key takeaways

Illegitimate children are compulsory heirs of their parent and have a protected legitime.
In both testate and intestate succession, the standard measure is: an illegitimate child receives half of a legitimate child’s share, except where special intestacy allocations apply (notably the spouse–illegitimate children 1/3–2/3 rule when there are no legitimate children).
Succession to “exclusive property” still requires correct estate formation: classification, liquidation (if married), deductions, then distribution.
The iron curtain rule sharply limits intestate inheritance between illegitimate heirs and the legitimate relatives of a parent—but it does not prevent an illegitimate child from inheriting from the parent.
A will cannot lawfully defeat compulsory heirship without a valid disinheritance; otherwise, the law enforces legitimes through reduction and related remedies.