How To Legitimize an Illegitimate Child in the Philippines

Is it possible that a child born as illegitimate can be considered legitimate?

Yes, there are two ways of raising the status of a child from illegitimate to legitimate, that is, going through the process of legitimation and adoption.

Let’s discuss each process one by one.

Go back to the main article: An Ultimate Guide to an Illegitimate Child’s Rights, Birth Registration, and Legitimization

DISCLAIMER: This article has been written for general informational purposes only and is not legal advice or a substitute for legal counsel. You should contact your attorney to obtain advice with respect to any particular issue or problem. The use of the information contained herein does not create an attorney-client relationship between the author and the user/reader.

Table of Contents


How To Legitimate an Illegitimate Child in the Philippines: 2 Ways

Raising the status of an illegitimate child to that of legitimate is important in cases of successional rights. It also bears importance in cases where the child was born prior to March 19, 2004 and the latter wants to use the surname of the father.

1. Legitimation

Legitimation is a process whereby an illegitimate child becomes legitimate by virtue of the marriage of his or her parents.

Sec. 177 of the Family Code provides that a child conceived and born outside of wedlock to parents, who, at the time of conception of the child, were not disqualified by any impediment to marry each other may be legitimated.

As amended by Republic Act 98581, a child born to parents who were below 18 years old may also be legitimated.

To summarize, legitimation has three requirements that must all be met in order for it to push through:

  • The child is born out of wedlock;
  • The child’s parents at the time of conception were not disqualified from marrying each, regardless if they’re both below or above 18 years of age;
  • A subsequent valid marriage between the parents of the child.

Example: You got pregnant by your boyfriend prior to you getting married and both of you have no impediment to marrying each other. The child is illegitimate but could be legitimated once you get married. In contrast, if both of you have an impediment to marrying each other at the time of conception and birth of the child (e.g. if you are in a bigamous marriage), the child can not be legitimated.

How does legitimation take place?

A child is legitimated by the subsequent valid marriage of the parents. Once legitimated, the child shall enjoy the same rights as a legitimate child. Please note that legitimation is retroactive. It means that the child becomes legitimate at the time of his birth, not at the time of marriage of the parents. (Sec. 178, 179,180, Family Code)

Steps to take in recording the legitimation of a child by subsequent marriage

Even though the marriage of your parents has upgraded your status from illegitimate to legitimate, you still need to go through the process of legitimation in order to officially change your status and be entitled to all the rights of a legitimate child.

1. Complete the following requirements for registration:

a. Certificate of Marriage

b. Certificate of Live Birth of the child

c. Affidavit of legitimation executed by both parents which shall contain the following facts:

  • Names of the parents;
  • The fact that at the time when the child was conceived, the parents could have contracted marriage, and that they subsequently contracted marriage;
  • The date and place of the marriage of the parent;
  • The name of the priest or solemnizing officer who officiated the marriage;
  • The name and municipality where such marriage was recorded
  • The name of the child to be legitimated and other facts of birth, and
  • The date and place where the birth of the child was registered.

2. Go to the Office of the Civil Registrar (the city or municipality) where the child was born.

3. Register the document.

4. Request a certified true copy of the PSA birth certificate once the process has been completed. Here are the effects of the legitimation:

  • The original family name of the child as appearing in the birth certificate shall not be erased or deleted.
  • In the remarks space of the COLB, the following shall be written: “Legitimated by Subsequent Marriage” indicating the family name which the child shall bear by virtue of the legitimation.

2. Adoption

Republic Act No. 85522 or the “Domestic Adoption Act of the Philippines” provides that an illegitimate son or daughter of a qualified adopter may be adopted to improve the child’s status to that of legitimacy.

Example: In a situation where the child could not be legitimated because the parents have an impediment to marry each other at the time of the child’s conception and birth, the parent could adopt his or her own child so that the latter is now elevated to the status of a legitimate child.

Effects of adoption

  • The child shall be considered the legitimate child of the adopting parent and thus entitled to all rights and obligations provided by law to a legitimate child
  • The effectivity of the decree of adoption shall be the date the petition for adoption was filed (Sec 13, RA 8552)
  • The original Certificate of Live Birth (COLB) of the child shall be stamped “canceled” with an annotation of the issuance of the amended COLB
  • An amended certificate of birth bearing the surname of the adopter shall be issued by the Civil Registry as required by the Rules of Court
  • All hearings in adoption cases shall be confidential and not open to the public. All records relating to the adoption proceedings shall be strictly confidential
  • The child shall have the same successional rights as the legitimate child

Frequently Asked Questions

1. I have an illegitimate child/children from a previous relationship. Now that I’m married, my spouse and I want to legitimize my illegitimate child/children. Can we do it through adoption?

Yes, you can legitimize the child through the process of adoption. Once adopted, the child shall become the legitimate child of the adopters, and shall acquire the reciprocal rights and obligations as a parent and child. 

2. The illegitimate child has been using the father’s surname. Legitimization is needed in order for the child to claim citizenship to the father’s country or to claim rights to the father’s inheritance. However, the father has already passed away. Can the illegitimate child still be legitimized?

No, the child can no longer be legitimized. Given the death of the father, both options for legitimization as discussed in the article above have become impossible. Legitimation, or raising the status of the child from illegitimate to legitimate, occurs when the parents, later on, entered into a valid marriage. An illegitimate child may also become legitimate through the process of adoption, i.e. the parent shall adopt his or her illegitimate child. This is done to raise the status of the child from illegitimate to legitimate, which has effects on successional rights, among others.

Before you can adopt an illegitimate child, you must ensure first that several persons have consented to the act of adoption, as required by law. 

According to Section 23 of Republic Act No. 11642 or the Domestic Administrative Adoption and Alternative Child Care Act3, the following people must provide written consent to the adoption after being properly counseled and informed of their right to approve or withdraw the approval of the said adoption:

  • The adoptee, if ten (10) years of age or over;
  • The biological parents of the child, if known, or the legal guardian, or the proper government instrumentality which has legal custody of the child, except in the case of a Filipino of legal age if, prior to the adoption, said person has been consistently considered and threated as their own child by the adopters for at least three (3) years;
  • The legitimate and adopted children, ten (10) years of age or over, of the adopters, if any;
  • The illegitimate children, ten (10) years of age or over, of the adopter if living with said adopter or over whom the adopter exercises parental authority and the latter’s spouse if any; and
  • The spouse, if any, of the person adopting or to be adopted.

According to our jurisprudence, the consent of these persons is necessary to maintain harmony among the family members. The adoption cannot push through if at least one of them withdraws their consent. 



  1. Republic Act No. 9858 (An Act Providing for the Legitimation of Children Born to Parents Below Marrying Age, Amending for the Purpose the Family Code of the Philippines, as Amended) (2009).
  2. Republic Act No. 8552 (Domestic Adoption Act of 1998) (1998).
  3. The Official Gazette of the Republic of the Philippines. Republic Act No. 11642 or the Domestic Administrative Adoption and Alternative Child Care Act (2022). Metro Manila.

Atty. Kareen Lucero

Kareen Lucero is a lawyer previously doing litigation before working for different agencies in the government and for a multinational corporation. She has traveled to 52+ countries including a 3-month solo backpacking in South East Asia and more than 1 year of solo traveling across four continents in the world. As part of giving back, she is passionate about sharing her knowledge of law and travel. She is currently doing consulting work for a government agency. For inquiries, you may reach her via Facebook Messenger ( or email ([email protected]).

37 thoughts on “How To Legitimize an Illegitimate Child in the Philippines

  1. Good day Atty. Karen.. What if the situation is like this. A mother have illegitimate children but acknowledge by the biological father so they uses Father’s surname but they got separated already.. What if in time the mother would marry other guy.could she still legitimized her children by adoption? What if the second man refuses to adopt the children? or the biological father didn’t allow it?does the mother itself can adopt her children and use her maiden name?if this allowed what would be the stand of those children in terms of inheritance?thank you so much atty.

  2. Hello po atty. Nagkaroon po aqo Ng baby sa boyfriend qo Hanggang nagkahiwalay na po kmi.
    And now my new partner gusto niya pong ipa epilyedo sa kanya ung unang baby ko kasi ito ‘y naka epilyedo sa kin
    Paano po maiilipat sa surname niya atty.,

  3. Thank you for this article.
    I have a follow up question in relation to adoption. I was supposed to be adopted to be legitimized daughter by my biological father and step mother however before it was completed, they died due to a tragic reason.
    After their death, there was an agreement made by the siblings of my father and step mother about the properties left and I was included in the written document then having the rights to the properties. My uncle was assigned to manage the properties while I finish my studies. Now, I learned that they are selling some of the properties and had removed my name from the agreement. I would like to know what extent can I assert my rights and what do I need to do. I’m looking forward to your advise.

    1. Hi Josh,

      Atty. Kareen is currently busy so she cannot personally answer readers’ comments for now. However, she’s already written extensively about this topic so you can just refer to the following articles:

      What are the inheritance rights of an illegitimate child in the Philippines?

      If your father left a will, you can also check this out:

      I still highly suggest that you reach out to a lawyer to determine if there are legal options available for you.

  4. I have a son. She was born illegitimate. We are not married that time but fortunately after, 4 year after giving birth me and my husband got married. Does I have to do the process for legitimatising even my son is carrying my husband surname?

  5. My brother had been living with the mother of his children before they were born. The mother had been married in 1969 and the husband left her in 1970. The marriage has not been annulled, so my brother and the mother of his children can not get married. If the mother was able to annul her marriage and they get married, how can the children change their birth certificates? They all indicated that they were legitimate children and indicated a marriage that never happened, (parents’ mistake).

  6. Atty.good day! I had an illegimate child which was born last Dec. Of 1999 under birth from Aug. 3,1988 to Mar. 18,2004.
    But with the revised IRR of R.A.9255 effective April 7, 2016 includes AUSF will be at the discretion of the court. May I know what does this implies or best to be interpreted. The registrar insisted for court order .My daughter is already using my surname in all her documents.
    Thank you and God bless

  7. Hello, the biological father of my son, has not been in contact with my wife since they conceived him almost 15 yrs ago. I supported little baby Ian since before he was born. My wife and I married when my son was only 3+ yrs old and we “legally legitimated” him in Manilla about 3 months later. Now my son’s American cousins are all inheriting money from his Arizona grandmother’s estate. Apparently, in Arizona, an “adopted child” has the same rights as his cousins legitimately born cousins and my mother’s Estate document does not disqualify adopted children. However, can my son qualify for inheritance even though we didn’t “formally adopt” him? Or, is he already considered adopted by virtue of “certified legitimation” which appears on his PI birth certificate? The issue is this: Does certified legitimization (in PI) = adoption with respect to inheritance rights in Arizona?

  8. Hello, can I ask this question because I don’t have any idea about how to legitimize an illegitimate child here in the Philippines especial in my case . The father of my child is not with me noong nanganak ako sa Hospital kasi nasa manila siya that time and hindi pa po kami kasal until now. Then they said na hindi po pwede ma acknowledge na e padala yung surname ng Father ng anak namin because I have to claim my SSS Maternity Benefits. So now, we’re planning to get married at para na din ma change na yung surname ng Anak namin sa father nya. tanong ko lang po gaano ka tagal po ba ang proseso at anu-ano ang mga dapat gawin or requirements para mag process ? and how much does it cost?. mahirap din po kasi pumunta sa civil registry office gawa nga po ng lockdown pa sa lugar.. so I prefer to ask online .
    thank you po and I hope my makuha po akong malinaw na sagot .

  9. Hi Atty. Karen.
    My daughter was conceived before my first marriage was annulled. Her father was single and never married. My annulment was finalized 2 months after her birth. I am now married to her father. She bears her father’s surname in the birth certificate as the father recognized paternity.
    Can we still apply for legitimation? Thank you.

Read more guides about illegitimate child: