(Philippine legal article; Civil Code + Family Code framework)
1) Core idea: illegitimate children are heirs—but with defined limits
Under Philippine law, an illegitimate child (a child conceived and/or born outside a valid marriage, and not subsequently legitimated or adopted as legitimate) can inherit from his or her parents. In fact, illegitimate children are compulsory heirs of their parents, meaning the law reserves for them a legitime (a mandatory minimum share) that generally cannot be taken away except through valid disinheritance.
Their rights, however, differ from those of legitimate children, especially in (a) the amount of their legitime, and (b) their ability to inherit intestate (without a will) from the legitimate relatives of their parents (the “iron curtain” rule).
Two major codes interact:
- Civil Code (on Succession): sets out legitimes, intestacy rules, disinheritance, representation, partition, etc.
- Family Code: modern rules on filiation and explicitly states the legitime of illegitimate children (modifying older Civil Code provisions).
2) Key terms you must understand
a) Testate vs. intestate succession
- Testate succession: the decedent left a valid will. Distribution follows the will but must respect legitimes.
- Intestate succession: no valid will (or the will doesn’t dispose of everything). Distribution follows the Civil Code’s intestacy rules.
b) Compulsory heirs and legitime
Compulsory heirs are those whom the law protects by reserving a legitime. Among them are:
- legitimate children/descendants;
- legitimate parents/ascendants (in certain cases);
- the surviving spouse;
- illegitimate children/descendants.
c) “Illegitimate” is not changed by surname use
Even if an illegitimate child is allowed to use the father’s surname (e.g., under laws on acknowledgment/surname), that does not automatically make the child legitimate. Legitimacy is a legal status created by valid marriage of parents at conception/birth or by legitimation (and adoption, which carries its own effects).
3) The fundamental rule on share: “half of a legitimate child”
The Family Code rule (dominant principle)
An illegitimate child’s legitime is one-half (1/2) of the legitime of a legitimate child.
This “half-share” principle appears in two practical settings:
In testate succession (with a will) The will must leave to the illegitimate child at least a legitime equal to half the legitime of a legitimate child in the same family situation.
In intestate succession (no will) When illegitimate children inherit together with legitimate children, each illegitimate child receives a share equal to one-half of the share of each legitimate child.
A very workable way to compute in mixed-child intestacy is the “unit method”:
- each legitimate child = 2 units
- each illegitimate child = 1 unit Divide the net estate by total units.
4) Intestate inheritance of illegitimate children: scenarios and computations
Scenario A: Only illegitimate children (no legitimate children), no spouse
If the decedent leaves only illegitimate children, they inherit the estate in equal shares.
Example: Net estate = ₱900,000; 3 illegitimate children Each gets ₱900,000 ÷ 3 = ₱300,000.
Scenario B: Legitimate and illegitimate children together (no spouse)
Apply the 2-unit / 1-unit rule.
Example: Net estate = ₱1,200,000
- 2 legitimate children → 2 units each = 4 units
- 2 illegitimate children → 1 unit each = 2 units Total units = 6 Value per unit = ₱1,200,000 ÷ 6 = ₱200,000
- each legitimate child gets 2 units = ₱400,000
- each illegitimate child gets 1 unit = ₱200,000
This expresses the statutory policy: an illegitimate child gets half of a legitimate child’s share when both inherit intestate from the same parent.
Scenario C: Illegitimate children + surviving spouse (no legitimate children)
When a surviving spouse concurs with illegitimate children only, intestacy rules allocate the estate between:
- the surviving spouse, and
- the illegitimate children.
A commonly applied distribution under the Civil Code’s intestacy scheme is:
- 1/3 to the surviving spouse
- 2/3 to the illegitimate children (shared equally among them)
Example: Net estate = ₱900,000; spouse + 3 illegitimate children
- spouse: 1/3 = ₱300,000
- illegitimate children: 2/3 = ₱600,000 → each gets ₱200,000
Scenario D: Legitimate children + illegitimate children + surviving spouse
Here, all three are heirs in intestacy, and you must reconcile:
- spouse’s intestate share rules, and
- the “half-share” rule between legitimate and illegitimate children.
A reliable practical approach is:
- determine the portion among the “children group” respecting the 2:1 ratio between legitimate and illegitimate children; and
- apply the spouse’s share rule for concurrence with legitimate children (spouse typically equals one legitimate child’s share in intestacy when legitimate children are present).
Because family fact patterns vary (number of children, whether there are descendants by representation, etc.), computations should be anchored on the exact Civil Code concurrence rule applicable, then applied with the 2:1 ratio for legit vs. illegit children.
5) The “Iron Curtain Rule” (Article 992, Civil Code): the most important limitation
a) The rule
Illegitimate children cannot inherit intestate from the legitimate relatives of their father or mother; and legitimate relatives cannot inherit intestate from the illegitimate child.
This is often called the “iron curtain” because it blocks intestate succession across the line between legitimacy and illegitimacy within the wider family.
b) What it means in plain terms
An illegitimate child may inherit intestate from:
- his/her mother and father (once filiation is established), and
- other illegitimate relatives in a line consistent with the law’s recognition.
But an illegitimate child is barred from inheriting intestate from the legitimate family of either parent—such as:
- legitimate grandparents,
- legitimate uncles/aunts,
- legitimate siblings (including legitimate half-siblings on the father’s or mother’s side), etc.
c) Representation does not usually “cure” the iron curtain
In intestate succession, “representation” allows descendants to step into the place of a deceased heir. However, the iron curtain rule has been applied to block attempts by an illegitimate descendant to inherit intestate from a legitimate relative of his/her parent through representation, because the prohibited relationship still exists.
d) Critical nuance: Article 992 is for intestate succession
The iron curtain rule is classically an intestacy bar. It does not automatically forbid a legitimate relative (e.g., a grandparent, aunt/uncle) from giving property to an illegitimate child by will, because testamentary freedom exists—subject to legitimes of that testator’s compulsory heirs and other limits in succession law.
So:
- Intestate: iron curtain blocks.
- Testate: a will can transmit property if the will is valid and legitimes are respected.
6) Testamentary succession: protecting the illegitimate child’s legitime
a) Illegitimate children as compulsory heirs of their parent
If the decedent is the child’s parent, the illegitimate child is a compulsory heir and must receive at least the minimum legitime provided by law (again, generally half of a legitimate child’s legitime).
A will that gives an illegitimate child less than the required legitime can be reduced through reduction of inofficious dispositions (the law cuts back excessive gifts/allocations that impair legitimes).
b) Preterition vs. impairment
If a compulsory heir is totally omitted in a will (a concept known as preterition, classically discussed for compulsory heirs “in the direct line”), consequences can include annulment of certain testamentary dispositions depending on the factual/legal classification. Even when preterition doctrine is debated in edge cases, the safer statement is this: a compulsory heir whose legitime is withheld has legal remedies to enforce it, whether by nullifying certain dispositions or by reduction to restore legitimes, depending on the structure of the will and the applicable Civil Code provisions.
c) Donations and lifetime transfers
Lifetime donations or transfers by the parent can still affect legitimes because the estate for legitime computation generally considers the net hereditary estate and applies collation/reduction rules when dispositions impair legitimes. An illegitimate child may challenge donations that effectively deprive him/her of the mandated legitime.
7) Disinheritance: how inheritance rights can be lawfully removed
An illegitimate child’s right to inherit (as compulsory heir of the parent) may be lost by:
- valid disinheritance in a will, or
- incapacity/unworthiness under the Civil Code (e.g., serious offenses against the decedent), when properly established.
Disinheritance must meet strict requirements
Disinheritance is not casual. Generally, it requires:
- a valid will,
- an express statement of disinheritance, and
- a legal ground recognized by the Civil Code for disinheritance of children/descendants, properly invoked and provable.
If the disinheritance is defective (wrong form, no valid ground, improper execution), the disinherited heir can assert rights to the legitime.
8) Establishing filiation: the gateway issue in inheritance cases
An illegitimate child cannot inherit from a person unless the law recognizes that person as the child’s parent.
a) Common ways filiation is established
Under the Family Code framework for illegitimate filiation, proof may come from:
- a record of birth showing recognition,
- an admission of filiation (public or private writing),
- open and continuous possession of status of a child,
- other admissible evidence consistent with rules (including, in appropriate cases, DNA evidence, subject to procedural rules and jurisprudence).
b) Timing matters: claiming from the estate
If the alleged parent dies without having acknowledged the child clearly, the child may need to file an action to establish filiation and assert hereditary rights against the estate—often within procedural timelines and estate settlement processes. Practically, the claim is raised in:
- judicial settlement of estate proceedings, or
- a separate action that affects settlement (depending on posture), so that the child can be included as an heir.
9) Illegitimate children vs. adopted and legitimated children
a) Legitimated children
If parents were not able to marry at the child’s conception but later become legally capable and subsequently marry (and other legal requirements are met), a child may become legitimated, which changes succession status.
b) Adopted children
Under Philippine adoption law, an adopted child generally acquires rights similar to a legitimate child of the adopter, including succession rights from the adoptive parents, subject to the governing statute and the adoption decree.
Because legitimation and adoption alter status, they can dramatically change:
- who are compulsory heirs,
- the legitimes, and
- intestate order of succession.
10) Practical consequences in estate settlement
a) Inclusion in extrajudicial settlement
Extrajudicial settlement (a common method when there is no will and no outstanding debts/complications) requires that all heirs are accounted for. Excluding an illegitimate child who is a legally recognized heir can expose the settlement to annulment/attack and can create civil and even potential criminal issues depending on misrepresentations.
b) Partition and delivery of shares
If an illegitimate child is an heir, the child is entitled to:
- participation in partition, and
- delivery of the share due (whether intestate share or legitime), and can challenge partitions that were simulated or executed without lawful inclusion.
c) Remedies
Typical remedies include:
- action to establish filiation (if disputed),
- action for annulment/reformation of settlement documents,
- action for reconveyance of property improperly transferred,
- petition in estate proceedings to be declared an heir and to receive the lawful share,
- reduction of inofficious donations/testamentary dispositions that impair legitimes.
11) Quick reference: what illegitimate children can and cannot do in succession
They can:
- inherit from their mother and father (once filiation is established), whether by intestacy or will;
- demand their legitime from a parent’s estate (as compulsory heirs);
- inherit by will from other persons if validly given and not barred by legitimes of that testator’s compulsory heirs;
- challenge estate distributions that unlawfully exclude them or impair their legitime.
They cannot (most notably):
- inherit intestate from the legitimate relatives of their parents (e.g., legitimate grandparents, legitimate siblings, legitimate uncles/aunts), due to the iron curtain rule;
- bypass legitime rules: even a favorable will cannot defeat other compulsory heirs’ legitimes, and an unfavorable will cannot deprive them of theirs unless validly disinherited or legally disqualified.
12) Bottom line
Philippine succession law treats illegitimate children as legally protected heirs of their parents through compulsory heirship and a guaranteed legitime, generally pegged at one-half the legitime of a legitimate child. The most consequential limitation is the iron curtain rule in intestacy, which blocks inheritance between illegitimate children and the legitimate relatives of their parents. In real disputes, the decisive issues are often (1) proof of filiation, and (2) correct application of (a) legitime rules and (b) intestate concurrence rules, especially when there is a surviving spouse and mixed legitimate/illegitimate descendants.