Legal grounds to question and impugn the legitimacy of a child

Persida Acosta

Persida Acosta

Dear PAO,
I am 25 years old and currently living in Laguna. My parents, though married, have been separated since I was five years old and it was my father who took care of me since then. Just recently, a person came to our house claiming that she is the daughter of my parents. My father is already frail but he undoubtedly knows that he does not have any other child. This person claims that my mother concealed her since birth, as she has no more face to show after leaving my father. How should we go about this? Is there a proper or legal way for me or my father to negate her claim that she is my sibling?

Dear Tess,
It is understandable that you and your father are perplexed and at the same time concerned by this revelation that you have another member of your family. It would, thus, be sensible for you and your father to ask this person who is claiming to be your sibling to present documents that can support her claims, such as her duly-authenticated birth certificate or record of birth as appearing in the civil register of the place where she was born. If it is disclosed from her record of birth that she was born at the time your parents were already married, then she is considered as their legitimate child in consonance with Article 164 (1) of the Family Code of the Philippines (FCP).

Nevertheless, your father may question and impugn the legitimacy of this person if he so desires, provided that he can establish that he was physically incapacitated to have sexual intercourse with your mother, or that there is a bona fide physical impossibility for him and your mother to have sexual intercourse considering that they have already separated. As provided for under Article 166 of the FCP: “Legitimacy of a child may be impugned only on the following grounds: (1) That it was physically impossible for the husband to have sexual intercourse with his wife within the first 120 days of the 300 days which immediately preceded the birth of the child because of: (a) the physical incapacity of the husband to have sexual intercourse with his wife; (b) the fact that the husband and wife were living separately in such a way that sexual intercourse was not possible; x x x”

It is also worth emphasizing that your father must file before the court the action to impugn the legitimacy of this person who is claiming to be his daughter within one year from the discovery or knowledge of the latter’s birth or of the fact of registration of the said birth, whichever is earlier, if he resides in the same city or municipality where the birth of the claimant took place or was recorded. If he resides in a different city or municipality in the Philippines, the action may be brought to court within two years from such discovery or knowledge; and three years if he lives abroad (Article 170, FCP).

We hope that we were able to answer your queries. Please be reminded that this advice is based solely on the facts you have narrated and our appreciation of the same. Our opinion may vary when other facts are changed or elaborated.

Editor’s note: Dear PAO is a daily column of the Public Attorney’s Office. Questions for Chief Acosta may be sent to


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  1. Good afternoon,

    ask ko lang po kung anong hakbang ang gagawin ko ,
    hindi ako kasal sa ama ng anak ko naka apelyedo sa kanya,gusto ko palitan ng apelyedo ko poseble po ba?

  2. Have a dna test & it will show if she is his daughter. There wasnt that a very simple answer. Why make a very simple problem complicated. She also has to pay to prove she is as he has no knowledge of her whatsoever.