Inheritance Rights of Illegitimate Children in the Philippines for a Grandparent’s Estate

Executive summary

In Philippine law, illegitimate grandchildren generally cannot inherit from a grandparent by intestacy (i.e., when there is no will) because of the Civil Code’s “iron curtain rule”. They may receive property from a grandparent by will (testate succession) or by lifetime transfers (donations) so long as the compulsory heirs’ legitimes are preserved. Illegitimate children are compulsory heirs only of their own parents, not of their grandparents.

This article unpacks the legal bases, the interaction of the Family Code and Civil Code, the main exceptions and workarounds, and the practical steps for families and practitioners.

Key statutes and concepts (plain-English guide)

Legitimate vs. illegitimate child Under the Family Code, a child conceived and born outside a valid marriage is illegitimate (unless legitimated/adopted). The Family Code consolidated the old Civil Code categories; for succession purposes today, the law simply uses legitimate or illegitimate.
Compulsory heirs & legitime In succession, certain heirs cannot be deprived of a legitime (a fixed minimum share) except for legally valid disinheritance. A grandparent’s compulsory heirs are typically:
1. the grandparent’s legitimate children/descendants,
2. the surviving spouse,
3. in their absence, the legitimate parents/ascendants, and
4. the grandparent’s illegitimate children. Illegitimate grandchildren are not compulsory heirs of the grandparent.
Illegitimate child’s fractional share (vis-à-vis their own parent) By law, an illegitimate child’s legitime is one-half (½) of what a legitimate child would get from the same parent. This ratio applies to the estate of their parent, not to the estate of a grandparent.
Representation Representation lets a descendant step into a predeceased ancestor’s place. However, representation is blocked across the “iron curtain” between an illegitimate person and the legitimate relatives of the parent through whom succession is claimed.

The “Iron Curtain Rule” (Civil Code Art. 992)

Rule: An illegitimate child has no right to inherit ab intestato (by intestacy) from the legitimate relatives of his/her father or mother—and vice versa.

Effect on grandparents’ estates:

If a grandparent dies without a will, an illegitimate grandchild cannot inherit intestate from that grandparent through the parent (even if that parent is the grandparent’s legitimate child).
The bar is reciprocal: legitimate ascendants and collateral relatives cannot inherit intestate from an illegitimate person and vice versa across that line.

What this does not do:

It does not stop a grandparent from giving by will to an illegitimate grandchild, because the text of Art. 992 is confined to intestacy.
It does not block lifetime donations or insurance designations—but those transfers remain subject to reduction if they impair the legitimes of compulsory heirs.

Testate succession (there is a will): how a grandparent may provide for an illegitimate grandchild

A grandparent may freely institute an illegitimate grandchild as heir, devisee, or legatee out of the free portion (the part of the estate not reserved as legitime to compulsory heirs). Key points:

Respect legitimes.
- If the grandparent leaves legitimate children/descendants, ½ of the estate is typically reserved as their collective legitime.
- The surviving spouse has his/her own legitime as well.
- Illegitimate children of the grandparent (i.e., decedent’s own illegitimate children) also have a legitime (equal to ½ of a legitimate child’s share from that decedent).
- Gifts in excess that encroach on those legitimes are reducible.
No compulsory status for illegitimate grandchildren.
- An illegitimate grandchild is not a compulsory heir of the grandparent; therefore, no guaranteed minimum share exists for them. Their participation depends on the will (or lifetime planning).
Tools a testator can use (properly structured):
- Institution of heir (universal share of the free portion).
- Legacy or devise (specific property or amount).
- Substitution and conditions (e.g., education milestones).
- Trusts and testamentary guardianship for minors or those needing stewardship.
Reduction and collation rules still apply.
- Large inter vivos donations to the grandchild may be brought to collation and reduced if they impair legitimes at death. Draft with those mandatory rules in mind.

Intestate succession (no will): typical outcomes

Because of Art. 992, in intestacy:

Illegitimate grandchildren do not take by representation from a legitimate grandparent. If a legitimate child of the grandparent predeceased, only that child’s legitimate descendants can represent. The predeceased child’s illegitimate descendants cannot.
Who takes instead? The estate devolves to the grandparent’s compulsory heirs by order of law (e.g., surviving spouse, legitimate children/descendants, legitimate parents/ascendants), excluding illegitimate grandchildren across the iron-curtain line.
Edge situations:
- If no compulsory heirs remain and the decedent left no will, succession moves through further legal orders (collaterals, the State). The iron curtain can still exclude illegitimate descendants attempting to claim through a legitimate line.

Filiation: proving the status that triggers or blocks rights

Whether one is illegitimate and through which parent matters enormously for Art. 992. Proof of filiation generally includes:

The record of birth showing filiation;
Admission of filiation in a public instrument;
Open and continuous possession of the status of a child; and
Judicial recognition (when contested).

Practice tip: establish filiation early and preserve documents. While actions involving filiation have nuanced rules on timing and evidence, timely recognition often spares families from costly succession litigation.

Practical planning strategies for grandparents who wish to benefit an illegitimate grandchild

Make a will early.
- Explicitly institute the grandchild for a share of the free portion or give a specific legacy.
- Coordinate the will’s dispositions with the mandatory legitimes of compulsory heirs to avoid reduction.
Use lifetime tools carefully.
- Donations (with or without conditions), education plans, and life insurance with the grandchild as beneficiary are common.
- Keep records and valuations; be mindful of inofficiousness (excess that can be reduced later).
Consider trusts and guardianship provisions.
- A testamentary or inter vivos trust can protect assets until the grandchild reaches a chosen age, with a trusted trustee and clear distribution standards.
Coordinate property regimes and titles.
- Double-check titles and the conjugal/absolute community status of assets to ensure what the grandparent is giving is actually theirs to give.
Tax and compliance.
- Donor’s tax applies to lifetime donations; estate tax applies at death. Plan timing and structure for efficiency and compliance (e.g., avail of allowable deductions and keep documentary completeness).

Common scenarios (qualitative outcomes)

Predeceased legitimate child leaves only an illegitimate child. Intestacy: the illegitimate grandchild does not inherit from the grandparent via representation (blocked by Art. 992). With a will: the grandparent may give that grandchild from the free portion.
Grandparent leaves legitimate children and also wants to benefit an illegitimate grandchild. With a will: possible—craft a legacy/devise out of the free portion, ensuring the legitimes of legitimate children and the spouse remain intact.
No will, no legitimate descendants, but there is an illegitimate grandchild across a legitimate line. Intestacy: the iron curtain may still bar that grandchild if the claim is through the legitimate parent. Succession proceeds to the next legal order.

Do’s and don’ts for families

Do:

Document filiation and keep civil registry records current.
Plan with a will if you intend to benefit an illegitimate grandchild.
Model the reductions (legitime math) before making sizable gifts.
Use trusts/insurance to deliver support securely and predictably.

Don’t:

Assume an illegitimate grandchild will inherit by default from a grandparent—they won’t in intestacy.
Make large donations without checking if they could be reduced later.
Overlook spousal and descendant legitimes; they are mandatory.

Frequently asked questions

1) Can an illegitimate grandchild ever be a compulsory heir of a grandparent? No. Compulsory-heir status of illegitimate children runs with respect to their own parents, not their grandparents.

2) Does the iron curtain apply if the grandparent leaves a will? Art. 992 bars intestate succession. A will is valid to benefit an illegitimate grandchild within the free portion and subject to legitimes and reduction rules.

3) What if the parent (child of the grandparent) was also illegitimate? The bar in Art. 992 is described as between an illegitimate person and the legitimate relatives of his/her parents. Outcomes can become technical depending on whether the relatives through whom one claims are legitimate or illegitimate; careful analysis of the particular family tree is needed.

4) Can lifetime donations to an illegitimate grandchild be attacked later? Yes, if they impair legitimes of compulsory heirs, they are reducible upon the donor’s death.

5) What about using the father’s surname—does that change inheritance from grandparents? No. Surname rules and recognition formalities do not override the iron curtain or the structure of compulsory heirs. They affect proof of filiation, not the hierarchy of heirs to a grandparent.

Practitioner checklist (when advising on a grandparent’s estate)

Map the family tree with legitimate/illegitimate status where relevant.
Inventory estate assets and characterize property (exclusive vs. conjugal/community).
Identify compulsory heirs and compute legitimes (high-level check first).
If planning, draft a will that grants for the illegitimate grandchild within the free portion.
If giving now, structure donations/trusts/insurance and keep documentary trail.
Flag potential reduction/collation issues; align expectations.
Address tax consequences (donor’s/estate tax) and compliance items.

Bottom line

For a grandparent’s estate, an illegitimate grandchild does not inherit by intestacy under Philippine law due to the iron curtain rule. That same grandchild can inherit by will (within the free portion) or via properly structured lifetime transfers, so long as the legitimes of compulsory heirs are respected. Thoughtful estate planning—early, documented, and coordinated—makes all the difference.