- Secure the following documents from the City/Municipal Civil Registrar’s Office (C/MCR) where the birth of the child was recorded:
- Affidavit of paternity/acknowledgement (Certified Photocopy/Xerox Copy)
- Joint affidavit of legitimation
- Certification of registration of legal instrument
- Certified joint true copy of birth certificate with remarks/annotation based on the legitimation by subsequent marriage.
- Verify the original birth certificate at the Philippine Statistics Authority (PSA). If it yields negative result, secure the birth certificate from C/MCR Office where the child was originally registered (Certified Photocopy).
- Verify the marriage contract of parents at PSA. If it yields negative result, secure the marriage contract from C/MCR Office where the marriage was solemnized (Certified True Copy).