nope. ang alam ko kailangan syang i-adopt parin ng partner mo kahit nakasulat sa birth certificate na sya yung tatay. 
^i-correct ko lang. QueenChokolah, hindi po ito yung situation na kakailanganin ang adoption. para maging LEGITIMATED ang anak nyo ito lang:
submit nso copy of your marriage certificate AND Joint Affidavit of Legitimation.
LEGITIMATED ang status niya. same rights as a legitimate child. pero siya: LEGITIMATED BY SUBSEQUENT MARRIAGE OF THE PARENTS.
ganito yung affidavit of legitimation, after preparing this and signing, pupunta kayong dalawa ng husband mo sa notary public para ipa-notarize. to be sure, prepare at least 5 copies.
JOINT AFFIDAVIT OF LEGITIMATION
WE, ______________ and ______________, both of legal age, Filipinos, husband and wife, respectively, and presently residing at _______________________ after having been duly sworn to in accordance with law, depose and state:
1. That we are the biological parents of _______________ who was born on ____________ in _____________ as evidenced by the attached copy of the child’s Birth Certificate, made an integral part hereof as Annex “A”;
2. That at the time of his/her birth, we, the biological parents were not yet married, hence his/her status in the original birth certificate was entered as Illegitimate.
3. That at the time of the conception of our child, there was no legal impediment for us to contract marriage;
4. That we contracted marriage on _____________ in ______________ which marriage was solemnized by _________________________, as evidenced by the attached Marriage Contract, made an integral part hereof as Annex “B”;
5. That by virtue of our subsequent marriage, the said child is now legitimated by operation of law, particularly Article 177 of the Family Code of the Philippines;
6. Hence, we are executing this Affidavit to attest to the foregoing facts, for purposes of complying with the requirements in applying for the legitimation by subsequent marriage of our son/daughter, _____________________ and for the proper recording of such legitimation in his/her civil registry documents and Philippine passport, to enable him/her to bear the surname of his/her father and be entitled to all the rights of a legitimated child, and for all legal intents and purposes.
IN WITNESS WHEREOF, we have hereunto set our hands this ___________________ in _______________, Philippines.
__________________
Affiant (father)
Philippine Passport No. _____
Issued at: ________________
Issued on: ________________
____________________
Affiant (mother)
Philippine Passport No. _____
Issued at: ________________
Issued on: _______________
SUBCRIBED AND SWORN TO before me this ___________________ in _________________, Philippines, affiants exhibiting to me their valid proofs of identification.
Doc. No. _____;
Page No. _____;
Book No. _____;
Series of 2015.
NOTE: DI NAMAN NECESSARY NA PASSPORT ANG GAMITIN NA I.D., ANY GOVERNMENT-ISSUED I.D. WILL DO. paphotocopy nyo na rin ang mga valid i.d. ninyo para ma-attach sa affidavit. attach nyo rin dito yung marriage contract na galing sa NSO.