Short answer. During the alleged parent's lifetime. Article 175 of the Family Code provides that when an illegitimate child's filiation relies on evidence that is not a formally signed document — such as open and continuous possession of the status of a child — the action must be brought while the parent is still alive.
What the law says
the action may be brought during the lifetime of the alleged parent.
Family Code, Article 175 — How Illegitimate Filiation Is Established. Read the full provision →
Two different deadlines depending on the evidence
Article 175 of the Family Code establishes that illegitimate children may prove their filiation using the same methods and evidence as legitimate children — but with an important timing difference that depends on the kind of evidence being used. When the evidence consists of a formal document — such as a birth record or a signed written acknowledgment by the parent — the action may be brought throughout the child's lifetime. But when the filiation relies on other evidence — such as open and continuous possession of the status, or other means — the action must be brought during the lifetime of the alleged parent.
Why the parent's lifetime is the deadline for informal evidence
The law draws this line because informal evidence of filiation — such as how the parent treated the child, whether the child was introduced as the parent's own, and other behavioural signs — is most reliably contested and examined while the alleged parent is alive. Once the parent dies, the clearest source of testimony about the relationship is gone. The stricter deadline protects against fabricated claims of parentage being asserted against an estate after the alleged parent can no longer respond.
What the brief refers to as 'unsigned acknowledgment'
Article 172 of the Family Code recognises that filiation can be established through a signed private handwritten instrument from the parent. An unsigned acknowledgment — something written but without the parent's signature — does not qualify as a formally signed document under the Code. Because it lacks the formal element that would place it in the category of signed documentary evidence, it falls into the category of other evidence, which means the action must be brought while the parent lives. An unsigned document may still be useful as evidence, but it does not carry the lifetime-action benefit of a signed one.
Acting before the deadline passes
If the alleged parent is still alive and you have not yet filed an action to establish filiation, the clock is running. The filing of the case — not the resolution of it — is what must happen within the parent's lifetime. Delay carries real risk: if the parent dies before the case is filed, the action may be barred entirely based on the kind of evidence you rely on. Gather your evidence now — documents, witness accounts, records of support or recognition — and consult a lawyer promptly to assess the strength of your case and file without unnecessary delay.
Cases citing this provision
These Supreme Court decisions cite the provision above. We list them so you can read them yourself; the summaries of what each decided are not ours to give.
- Romeo F. Ara and William A. Garcia vs. Dra. Fely S. Pizarro and Henry Rossi, G.R. No. 187273, February 15, 2017 — read the decision on LawPhil →
- Michael C. Guy vs. Hon. Court of Appeals, et al, G.R. No. 163707, September 15, 2006 — read the decision on LawPhil →
- Alejandra Arado, et al. vs. Anacleto Alcoran and Elenette Sunjaco, G.R. No. 163362, July 8, 2015 — read the decision on LawPhil →
- Narciso Salas vs. Annabelle Matusalem, G.R. No. 180284, September 11, 2013 — read the decision on LawPhil →