Short answer. Only a person prejudiced in their own rights may impugn a legitimation, and they have five years from the time their cause of action accrues. Disapproval, family grievance or a general belief that the record is wrong gives nobody standing to bring the action.
What the law says
Legitimation may be impugned only by those who are prejudiced in their rights, within five years from the time their cause of action accrues.
Family Code, Article 182 — Who May Impugn a Legitimation. Read the full provision →
Standing is the first hurdle, and most challengers fail it
The article allows a legitimation to be impugned only by those who are prejudiced in their rights. The word only is a deliberate narrowing. It is not enough to be a relative, to have views about the parents' marriage, or to think the registry entry inaccurate. The challenger must show a right of their own that the legitimation diminishes, which in practice usually means a successional interest that shrinks because another compulsory heir has appeared. A person with no such right cannot bring the action however well informed they are.
Five years, counted from accrual rather than from the event
The period is five years from the time their cause of action accrues, and that is not the same as five years from the legitimation. A cause of action accrues when the challenger's own right is actually prejudiced, which for an heir is typically when the succession opens and the shares fall to be determined, not when the parents married years earlier. So a legitimation recorded a decade ago is not automatically beyond challenge, and equally a challenger who sat on a live grievance for six years is out of time even if the legitimation is recent.
What such a case is really about
Impugning a legitimation means attacking the conditions on which it rested, most obviously whether the person legitimated is in fact the child of those parents and whether the marriage that triggered it exists and is valid. It is not a review of whether the arrangement seems fair. Because legitimation retroacts to the child's birth, a successful challenge unsettles a status that other decisions may have been built on, which is one reason the law confines the action to the genuinely prejudiced and closes it after a fixed period.
If you have been told a challenge is coming
The defence is documentary and it is largely built in advance. Secure certified copies of the birth certificate as it now stands, the parents' marriage certificate and any registry annotation reflecting the legitimation, and keep proof of when each was issued. Then work out, with a lawyer, the date on which the other side's cause of action accrued, because the five-year period is frequently the shortest route to ending the matter. A challenge brought late fails without the court ever reaching the merits.
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.
- Republic of the Philippines vs. Oliver M. Boquiren and Roselyn M. Boquiren, Duly Represented By Her Mother Rosalinda B. Macaraeg, G.R. No. 250199, February 13, 2023 — read the decision on LawPhil →
- Republic of the Philippines vs. Linney Jean L. Tangarorang and Ramer R. Tangarorang, G.R. No. 272006, February 5, 2025 — read the decision on LawPhil →