Inheritance Rights of Illegitimate Children vs. Legitimate Heirs (Philippine Law)

1) Why this matters

Succession in the Philippines is largely mandatory: certain relatives—called compulsory heirs—cannot be deprived of their legitime (reserved portion of the estate) except for strictly defined causes. Knowing how illegitimate children stand vis-à-vis legitimate heirs is crucial for estate planning, drafting wills, and settling estates (testate or intestate).

2) Core legal sources

Civil Code of the Philippines (Book III, Succession; key articles on legitimes, representation, intestacy).
Family Code (provisions on filiation, legitimation, effects of illegitimacy).
Republic Act No. 9255 (2004) (use of the father’s surname by an illegitimate child—does not equal legitimation).
Special rules and jurisprudence on the “iron curtain rule” (Art. 992 Civil Code), DNA evidence, and time limits for establishing filiation.

(Citations below are article numbers and doctrines; exact case names and evolving holdings are noted where essential.)

3) Who are the compulsory heirs?

Compulsory heirs generally include:

Legitimate children and descendants
Legitimate parents and ascendants (if no legitimate descendants)
Surviving spouse
Illegitimate children

They may concur with each other depending on who survives the decedent. Siblings are not compulsory heirs (they inherit intestate only when closer heirs are absent).

4) Establishing status (filiation) of an illegitimate child

An illegitimate child is one conceived and/or born outside a valid marriage, including those whose parents were disqualified to marry each other at conception (e.g., one parent was married to someone else). Core points:

Proof of filiation may be by:
- Civil registry records (birth certificate indicating filiation),
- Written admissions,
- Open and continuous possession of status as a child,
- DNA evidence (recognized by Rules on Evidence and jurisprudence).
Actions to establish filiation are generally personal and should be brought during the child’s lifetime (with narrow exceptions recognized by case law).
RA 9255 (use of father’s surname if acknowledged) does not confer legitimacy nor affect the amount of the child’s legitime.

5) Testate succession: legitimes and the free portion

5.1 Legitime of legitimate children and descendants

The collective legitime of legitimate descendants is ½ of the estate, divided equally among them.
The surviving spouse, when concurring with legitimate children, has a legitime equal to one legitimate child (this is taken from the free portion, not from the children’s ½).

5.2 Legitime of illegitimate children

Each illegitimate child’s legitime = one-half of the legitime of a legitimate child (the classic rule reflected in Art. 895).
- Practical translation: if a legitimate child’s legitime is X, an illegitimate child’s legitime is X/2.
When legitimate and illegitimate children concur, their legitimes are computed side-by-side and the free portion absorbs the spouse’s legitime and any remaining shares. If the sum of all legitimes exceeds the estate, reduction (abatement) is required, starting with inofficious donations and testamentary dispositions.

5.3 Surviving spouse (quick reference)

With legitimate children: spouse gets a share equal to one legitimate child (drawn from the free portion).
With legitimate parents/ascendants (no descendants): spouse’s legitime is ¼ of the estate.
With illegitimate children only (no legitimate descendants/ascendants): traditional rule gives the spouse a fixed legitime (often taught as ⅓) coexisting with the illegitimate children’s collective legitime; then the free portion fills the rest, subject to reduction if over-allocated. (Exact computations depend on the precise family mix; see worked examples below.)

Tip: Always compute (a) the compulsory legitimes first, (b) what remains as the free portion, and (c) apply abatement if totals exceed 100%.

6) Intestate succession (no valid will)

Order of intestate heirs (simplified):

Legitimate children and descendants.
In their absence: Legitimate parents/ascendants.
Illegitimate children (subject to the Art. 992 “iron curtain” in cross-line scenarios—see §7).
Surviving spouse participates in various orders and proportions depending on who else survives.
Collateral relatives (e.g., legitimate siblings) only if closer heirs are absent.

Key points for illegitimate children in intestacy:

If there are no legitimate descendants or ascendants, illegitimate children inherit by intestacy (in equal shares among themselves), subject to the spouse’s concurrent share when present.
Representation: Illegitimate children generally inherit by right of their own relationship with the decedent (their parent). Representation rules are narrower when crossing the legitimate–illegitimate line due to Art. 992 (below).

7) The “iron curtain rule” (Art. 992 Civil Code) and its evolution

Art. 992 historically prohibits intestate succession between a legitimate family line and an illegitimate family line—i.e., “no succession ab intestato between the illegitimate child and the legitimate relatives of his/her parent.” Practical effects:

An illegitimate child cannot inherit intestate from legitimate grandparents through the child’s legitimate parent (no representation across the line).
Conversely, a legitimate grandchild cannot inherit intestate from an illegitimate grandparent by representing his/her legitimate parent.

Jurisprudence has actively debated the scope, justification, and modern viability of this rule—especially in light of the Constitution’s equal-protection principles and statutory reforms that removed old labels among illegitimate children. Some decisions have read Article 992 strictly; others have discussed possible limits or re-thinking (e.g., when the bar should not apply, or when the claim is not pure intestacy).

Practice pointer: Because appellate rulings have not always been uniform and the Supreme Court has revisited this area, treat Art. 992 as a potential litigation hotspot. Where cross-line claims arise (e.g., an illegitimate grandchild seeking to succeed to a legitimate grandparent), expect objections grounded on Art. 992 and be ready with constitutional and policy arguments if you plan to challenge it.

8) Legitimation and adoption

8.1 Legitimation by subsequent valid marriage

A child conceived and born outside marriage to parents who, at conception, were not disqualified to marry each other, becomes legitimate upon the parents’ subsequent valid marriage, with effects retroactive to birth.
Not eligible for legitimation: children conceived when either parent was married to someone else (adulterous/concubinage).
Once legitimated, the child’s rights (including succession) are those of a legitimate child.

8.2 Adoption

Legal adoption generally confers on the adoptee the rights of a legitimate child with respect to the adopter, including in succession.
Adoption does not create inheritance rights between the adoptee and the adopter’s collateral relatives unless otherwise provided by law; but it does create full succession rights as to the adopter’s estate.

9) Worked computations (quick models)

Assumptions: No donations inter vivos; estate net of debts/taxes is the “free mass.” Where the totals overshoot 100%, apply abatement proportionately, starting with inofficious dispositions.

Model A — 1 legitimate child (LC), 1 illegitimate child (IC), and a spouse (S)

Legitimate child’s legitime (collective): ½ → LC gets ½.
IC’s legitime: ½ of a legitimate child’s legitime = ¼ (since the LC’s legitime is ½, the IC’s individual legitime is ¼ of the estate).
Spouse’s legitime: equal to 1 LC share, drawn from the free portion. Here, 1 LC share (if there were two LCs) would be ½ of the ½ legitime = ¼ of the estate.
Totals so far: ½ (LC) + ¼ (IC) + ¼ (S) = 1.00 (no free portion left).
Distribution: LC ½, IC ¼, S ¼.

Model B — 2 legitimate children (LC1, LC2), 2 illegitimate children (IC1, IC2), and spouse (S)

LC collective legitime = ½ ⇒ each LC gets ¼.
Each IC’s legitime = ½ of an LC’s legitime = ⅛. Two ICs ⇒ ¼ total for ICs.
Spouse’s legitime (equal to one LC share) = ¼ (from the free portion).
Totals: ½ (LCs) + ¼ (ICs) + ¼ (S) = 1.00 (no free portion left).
Distribution: LC1 ¼, LC2 ¼; IC1 ⅛, IC2 ⅛; S ¼.

Model C — No legitimate descendants or ascendants; 3 illegitimate children (IC1–IC3) and spouse (S)

Traditional approach: allocate the spouse’s fixed legitime in concurrence with illegitimate children (often taught as ⅓ to spouse; ⅓ as the collective legitime of the ICs; remaining ⅓ as free portion**).
With no will, intestacy fills the entire estate; the ICs take in equal shares subject to the spouse’s intestate share. In many computations, outcomes converge around S ~ ¼–⅓ and ICs share the remainder equally, but the precise figure depends on whether you are doing legitime-based testate math or intestate math for that family mix.
Practical step: run both testate-legitime and intestate frameworks and ensure the solution respects compulsory shares and the absence of closer heirs.

Remember: These are templates, not substitutes for a full article-by-article computation when other heirs (e.g., legitimate ascendants, acknowledged donations, preterition issues) are present.

10) Donations, preterition, and reduction

Donations inter vivos (gifts made during the decedent’s lifetime) that impair legitimes are reduced (partly invalid) after death to restore compulsory portions.
Preterition (total omission of a compulsory heir in a will) can annul the institution of heirs (wholly or partly), depending on who is preterited (especially legitimate children/descendants). Illegitimate children who are compulsory heirs also trigger remedies if omitted and their legitime is impaired.

11) Disinheritance

Possible only for statutory causes (e.g., serious offenses against the decedent or close family).
Must be express in a valid will, stating a specific legal ground; otherwise ineffective, and the compulsory heir still takes his/her legitime.

12) Taxes and settlement mechanics (practical)

Estate tax (TRAIN/CREATE regime): 6% of the net estate (subject to standard deductions/exemptions), payable by the estate.
Settlement paths:
- Extrajudicial settlement (if no will, no debts, all heirs of full age and agree),
- Summary/special proceedings (probate of will or letters of administration),
- Partition (voluntary or judicial).
Heirs can waive or assign shares (post-death), but cannot contractually waive compulsory rights in advance.

13) Practical checklist

Identify heirs and classify (legitimate vs. illegitimate; spouse; ascendants).
Establish filiation (documents, admissions, status, DNA if needed).
Compute legitimes (legitimate descendants → ½; each illegitimate child → ½ of a legitimate child’s legitime; spouse → rules by concurrence).
Account for donations made during decedent’s lifetime.
Determine the free portion and check if any testamentary dispositions are inofficious (then reduce).
Watch for Art. 992 issues when claims cross the legitimate–illegitimate line (especially intestate representation to/from grandparents).
Finalize distribution; prepare deeds (extrajudicial settlement or partition) and file estate tax.

14) Key contrasts—at a glance

Topic	Legitimate Child	Illegitimate Child
Status	Born/conceived within valid marriage (or legitimated/adopted)	Born/conceived outside valid marriage; not legitimated
Compulsory-heir?	Yes	Yes
Individual legitime	Baseline for comparison	½ of a legitimate child’s legitime
Concurrence with spouse	Spouse gets share = one legitimate child (from free portion)	Same spouse rule; IC’s legitime remains half of LC’s legitime
Representation upward/downward	Full within legitimate line	Limited by Art. 992 for cross-line intestacy (no intestate succession with legitimate relatives of the parent)
Surname	Follows father by presumption of paternity; or per registry	May use father’s surname under RA 9255 if requirements met; does not change share
Ability to be totally disinherited	No, except for statutory causes	No, except for statutory causes

15) Final takeaways

Illegitimate children are compulsory heirs. Their individual legitime is one-half of what a legitimate child would receive.
The surviving spouse’s share depends on who else survives; with legitimate children, it equals one legitimate child (taken from the free portion).
The iron curtain rule (Art. 992) remains a pivotal (and contested) constraint in intestate cases crossing the legitimate–illegitimate line. Expect legal argument here.
Legitimation (by subsequent valid marriage) and adoption can convert the child’s status to legitimate, changing the computation.
Always prove filiation early, compute legitimes first, then test any will or donations against those mandatory shares and apply reduction as needed.

This article is a practitioner-style overview for Philippine succession matters. For any live estate, run the full article-by-article computation with the exact family tree, lifetime donations, and documents on filiation and marital status.