Abstract

This article explains, in practical detail, how Philippine succession law treats (a) illegitimate children and (b) a common-law partner (live-in partner; partner in a void union). It covers testate and intestate succession, legitimes and free portions, proof of filiation, interaction with the property rules on unions without marriage (Family Code arts. 147/148), limits on gifts to a partner, and step-by-step estate liquidation when the decedent dies leaving a live-in partner and children born out of wedlock.

I. Core Concepts and Statuses

Illegitimate child A child not conceived or born within a valid marriage. Under the Family Code, the former sub-labels (“natural,” “spurious”) are abolished for succession purposes. Illegitimate children are compulsory heirs of their parents.
Common-law spouse / live-in partner There is no “spouse” in law unless there is a valid marriage. A live-in partner is not a compulsory heir and does not inherit by intestacy. Their property rights arise not from succession, but from co-ownership of properties acquired during cohabitation (Family Code arts. 147 or 148), and from any valid testamentary gifts within the free portion (subject to restrictions explained below).
Compulsory heirs (for context)

Legitimate children/descendants;
In their absence, legitimate parents/ascendants;
Surviving spouse (only if validly married);
Illegitimate children. These heirs are entitled to legitimes (reserved shares) that a will cannot impair.

II. Intestate vs. Testate Succession

Intestate (no will): The Civil Code’s order of heirs applies. Illegitimate children inherit from their parent; a live-in partner does not.
Testate (with a will): The testator may give property to anyone only up to the free portion after setting aside all legitimes. A legacy to a common-law partner is valid only if not disqualified (see §VII) and only within the free portion.

III. Illegitimate Children: Shares and Limits

A. Legitime (baseline rule)

The legitime of an illegitimate child is one-half (½) of the legitime of a legitimate child. Practically, this yields the classic formulas:

If the decedent leaves only illegitimate child/ren (no legal spouse; no legitimate child/ren; no legitimate parents): They take the entire estate in equal shares by intestacy (after debts and after liquidating any cohabitation co-ownership per arts. 147/148).
If there are both legitimate and illegitimate children (no legal spouse): First reserve ½ of the estate for the legitime of the legitimate children (to be divided among them). Then reserve ¼ for all illegitimate children (equal shares among them). The remaining ¼ is the free portion.
If there are legitimate children and a surviving legal spouse (valid marriage) plus illegitimate child/ren: The spouse’s legitime equals that of one legitimate child and is taken from the ½ reserved for legitimate descendants; illegitimate children still take ¼ (collectively); ¼ remains free portion. (Included here for orientation; in the main scenarios below we assume no valid spouse.)
If there are no descendants but there are legitimate parents/ascendants: Legitimate ascendants are compulsory heirs; the illegitimate child is also a compulsory heir of the decedent-parent. The legitimes must be fitted together; in intestacy, civil-code rules allocate shares so that ascendants and illegitimate children participate. (In practice, if an unmarried person dies leaving an illegitimate child, the child inherits ahead of ascendants in intestacy; if contest arises, courts harmonize the compulsory shares and free portion.)

B. Equal treatment among illegitimate children

All illegitimate children of the decedent—regardless of the other parent—share equally with each other in their collective portion.

C. Representation, collateral relatives, and the “iron-curtain” rule

Illegitimate children inherit from their parents; their descendants represent them in the direct line (e.g., an illegitimate child’s child may step into their place if the illegitimate child predeceases the decedent).
The long-standing Article 992 barrier (“iron curtain”) bars intestate succession between an illegitimate child and the legitimate relatives of the child’s parent, and vice-versa. (This rule has been criticized; always verify if a later case has modified it for your facts, but the conservative, traditional statement is: the barrier applies.)

D. Proof of filiation (critical in estates)

An alleged illegitimate child must establish filiation, typically by: civil registry records, authentic writings of parentage/acknowledgment, open and continuous possession of the status of a child, DNA, and other Family Code modes. Actions to prove filiation are generally not time-barred during the parent’s lifetime; after death, courts allow proof in the estate case subject to evidentiary standards.

IV. The Common-Law Partner: What They Do (and Do Not) Inherit

A. No intestate share

A live-in partner does not inherit by operation of law. There is no “surviving spouse’s share” without a valid marriage.

B. Property rights outside succession (Family Code arts. 147/148)

Before talking about inheritance, liquidate the cohabitation property regime:

Article 147 (both parties were free to marry each other):
- Properties acquired through their joint efforts, work, or industry, and fruits thereof, are co-owned.
- Equal shares are presumed unless there is proof of unequal contribution.
- Exclusive properties remain exclusive (e.g., brought into the relationship or acquired by gratuitous title).
- Upon death, the decedent’s ½ (or proven share) in the co-owned properties enters the estate; the survivor keeps their own share directly and outside inheritance.
Article 148 (there was a legal impediment; e.g., one/both were married to someone else):
- Only properties acquired by actual joint contribution of money, property, or industry are co-owned, in proportion to each party’s contributions.
- No presumption of equal shares; the survivor must prove contribution.
- Properties exclusively acquired by one remain exclusively theirs.
- The decedent’s proven share, after liquidation, goes to the estate.

Practical order of operations: (i) Identify and separate exclusive properties; (ii) Liquidate the art. 147/148 co-ownership; (iii) Only the decedent’s net share then becomes the successional estate to be divided among heirs (e.g., children).

C. Testamentary gifts to the partner (free portion only; see disqualifications)

A testator may leave to a live-in partner a legacy within the free portion, provided the partner is not legally disqualified (see §VII) and legitimes of compulsory heirs are intact.

V. Donations and Lifetime Transfers to a Partner

Between persons who may marry each other (art. 147 situations): Ordinary donations inter vivos are generally valid up to the value limits (the donor cannot impair the future legitimes of compulsory heirs; such donations may later be reduced in collation if they in fact impair legitimes).
Between persons in an adulterous/concubinage relationship (art. 148 situations): Donations between persons guilty of adultery or concubinage at the time of donation are void. This incapacity also extends to testamentary provisions, meaning a will favoring a paramour in such a relationship is vulnerable/void under the Civil Code.
Practical effect: If either partner was married to someone else during the liaison, lifetime gifts and even will provisions in favor of the other can be struck down; the partner must rely on co-ownership rights (arts. 147/148), not gifts.

VI. How an Estate with a Live-In Partner and Illegitimate Child Is Actually Settled

Step 1: Identify and pay debts/expenses. Funeral, last illness, taxes, debts, administration expenses are paid before any distribution.

Step 2: Carve out the partner’s non-successional share.

Liquidate the art. 147/148 co-ownership. The survivor receives their own share of co-owned assets (equal presumption under art. 147; proportional under art. 148).
Only the decedent’s share proceeds to succession.

Step 3: Determine heirs and compulsory shares.

If the only heirs are illegitimate child/ren (no valid spouse, no legitimate descendants, and no superseding heirs), they take the estate residue in equal parts.
If there is a will, verify that legitimes of any compulsory heirs (including illegitimate child/ren) are intact; any excess gifts to the partner are reduced.

Step 4: Partition and transfer. Execute extrajudicial settlement (if allowed) or seek intestate/testate proceedings. Transfer titles to heirs; compute and pay estate and documentary taxes.

VII. Disqualifications and Incapacities Affecting a Partner’s Share

No marriage = no spousal legitime.
Paramour rule: Donations inter vivos and mortis causa (via will) are void if the partners were guilty of adultery/concubinage at the time of donation/legacy.
Public-policy bars: Dispositions contrary to law, public order, or good customs are void.
Illicit cause ≠ art. 147/148 co-ownership: Even if a legacy is void, the survivor’s co-ownership rights in properties acquired by joint industry remain (subject to the specific article that applies).

VIII. Worked Examples (Simplified)

Example 1 — Unmarried decedent; one live-in partner (both free to marry); two illegitimate children

House (₱6M) acquired through joint efforts during cohabitation (art. 147) → co-owned 50/50 presumed.
Car (₱1M) bought by decedent alone → exclusive.
Debts: ₱1M.

Liquidation:

Co-ownership: House split ₱3M (partner) / ₱3M (estate).
Estate assets: ₱3M (house share) + ₱1M (car) = ₱4M.
Less debts (₱1M) = ₱3M estate residue. Heirs: two illegitimate children → ₱1.5M each. The partner gets ₱3M as co-owner, not as heir.

Example 2 — Same facts, but there is a will leaving “all” to the partner

The will cannot impair the illegitimate children’s legitimes. At minimum, each illegitimate child takes a legitime equal to ½ of a legitimate child’s legitime in the scenario’s math; here, with no legitimate heirs, they will effectively take the entire estate residue after debts—so the universal legacy to the partner is reduced to zero as to the estate portion. The partner still keeps their co-ownership share (₱3M) off the top.

Example 3 — Union with impediment (art. 148); partner cannot prove contribution

Property acquired during cohabitation counts as co-owned only to the extent of proven contribution. If the surviving partner proves no contribution, they get none of that asset via co-ownership. Heirs take it through the estate (subject to debts).

IX. Practical Checklists

For an Illegitimate Child Claiming as Heir

Filiation proofs (PSA birth certificate, authentic acknowledgments, DNA if needed, testimony of open and continuous possession).
Estate documents (death certificate, debt list, asset list, titles).
If there is a live-in partner, insist on prior liquidation of the art. 147/148 co-ownership, then compute shares.
If a will favors the partner, seek reduction to restore legitimes.

For a Surviving Live-In Partner

Identify whether art. 147 (both free to marry) or art. 148 (with impediment) applies.
Gather proofs of contribution (income records, receipts, bank transfers, payroll, testimonies).
Segregate exclusive properties and co-owned assets; liquidate co-ownership before the estate partition.
Be cautious with gifts: donations/legacies may be void if the relationship fell under art. 148 (adulterous/concubinage).

X. Common Misconceptions

“A live-in partner is a ‘spouse’ for inheritance.” False. No valid marriage, no spousal legitime.
“A will can give everything to the partner.” Not if there are compulsory heirs (e.g., illegitimate child/ren). The free portion only may be used—and even that may be void in adulterous relationships.
“All properties during cohabitation are 50/50.” Only in art. 147 with a presumption of equality; in art. 148, prove contributions.
“If the child wasn’t acknowledged, they cannot inherit.” The child must prove filiation, but acknowledgment is not the only mode of proof (civil registry, authentic writings, status, DNA, etc.).

XI. Step-By-Step Estate Roadmap (When There’s a Live-In Partner)

Inventory debts and assets; protect and insure estate property.
Classify assets: exclusive of each partner vs. co-owned (art. 147/148).
Liquidate co-ownership; deliver survivor’s share outside the estate.
Compute estate residue; determine compulsory heirs (e.g., illegitimate child/ren).
Apply legitimes/free portion; reduce any excessive donations/legacies.
Partition/transfer via extrajudicial settlement (if allowed) or court.
Tax compliance: estate tax return, DST, and title transfers.

XII. Key Takeaways

Illegitimate children are compulsory heirs of their parents and may take the entire estate in intestacy when they are the only heirs after debts and post-cohabitation liquidation.
A common-law partner is not a legal spouse and does not inherit by intestacy; their protection comes from co-ownership under arts. 147/148 and, where allowed, free-portion legacies (subject to paramour-rule disqualifications).
Always liquidate the 147/148 co-ownership first; only the decedent’s net share enters succession.
Gifts between paramours (adultery/concubinage) are generally void, even by will.
Filiation proof is the linchpin for an illegitimate child’s rights; prepare documentation early.

This article offers general guidance on Philippine succession and family property law. Complex estates—especially those involving multiple families, void marriages, donations, or disputed filiation—require tailored legal advice and careful evidence management.