My boyfriend and I had a child four years ago. Because we were not married, I registered my son's birth certificate under my surname. Three years ago, we got married, and we now want our son to use my husband's surname. How do I go about this?
The simplest way is for the father to prepare a document, in his own handwriting, recognizing the child as his own. He should submit this to the civil registrar where the birth certificate was registered, together with an "Affidavit to use the surname of the father."
The basis of this is Republic Act No. 9255 issued on February 24, 2004 which amended Article 176 of the Family Code of the Philippines as to read:
"Article 176. Illegitimate children shall use the surname and shall be under the parental authority of their mother, and shall be entitled to support in conformity with this Code. However, illegitimate children may use the surname of their father if their filiation has been expressly recognized by the father through the record of birth appearing in the civil register, or when an admission in a public document or private handwritten instrument is made by the father..."
For details, check out the website of the Philippine Statistics Authority at https://psa.gov.ph/civilregistration/problems-and-solutions/birth-certificate-already-registered-and-child-under-0