One question that surely lingers in one's mind when talking about illegitimate children is the use of the father's surname even when parents are not married. The good news is, the mother of the child need not be married to the father for the child to bear the father's surname. However, the child will only be allowed to use it if the child's paternity has been recognised.
Here are the requirements you need to prepare:
1. Valid identification for both parents;
2. Affidavit to Use the Surname of the Father (AUSF);
3. Certified True Copy of the Certificate of Live Birth of the child;
4. Affidavit of Admission of Paternity or the Affidavit of Acknowledgment
Additional details of the process are outlined in Republic Act No. 9255
"Rule 3. Who may file
Under these rules, the father, mother, child if of age, or the guardian, may file the public document or Affidavit to Use the Surname of the Father (AUSF) in order for the child to use the surname of the father.
Rule 4. Where to file
4.1. The public document or AUSF executed within the Philippines shall be filed at the Local Civil Registry Office (LCRO) where the child was born, if the birth occurred within the Philippines.
4.2. The public document or AUSF executed outside the Philippines shall be filed at the LCRO of Manila, if the birth occurred within the Philippines.
4.3. The public document or AUSF whether executed within or outside the Philippines shall be filed at the LCRO of Manila, if the birth occurred outside the Philippines.
Rule 5. What to file
The following shall be filed at the LCRO:
5.1. Certificate of Live Birth with accomplished Affidavit of Acknowledgement/ Admission of Paternity at the back
5.2. Public document
5.3. AUSF, including all supporting documents
Rule 6. When to register
The public document not made on the record of birth, or the AUSF shall be registered within twenty (20) days from the date of execution at the place where the birth was registered. Otherwise the procedures of late registration shall be applied.
Rule 7. Requirements for the Child to Use the Surname of the Father
7.1 For Births Not Yet Registered
7.1.1 The illegitimate child shall use the surname of the father if a public document is executed
by the father, either at the back of the Certificate of Live Birth or in a separate document.
7.1.2 If admission of paternity is made through a private handwritten instrument, the child shall
use the surname of the father, provided the registration is supported by the following
documents:
a. AUSF
b. Consent of the child, if 18 years old and over at the time of the filing of the document
c. Any two of the following documents showing clearly the paternity between the father
and the child:
1) Employment records
2) SSS/GSIS records
3) Insurance
4) Certification of membership in any organization
5) Statement of Assets and Liabilities
6) Income Tax Return (ITR)
7.2 For Births Previously Registered under the Surname of the Mother
7.2.1 If filiation has been expressly recognized by the father, the child shall use the surname
of the father upon the submission of the accomplished AUSF.
7.2.2 If filiation has not been expressly recognized by the father, the child shall use the
surname of father upon submission of a public document or a private handwritten
instrument supported by the documents listed in Rule 7.1.2.
7.3 Except in Item 7.2.1, the consent of the illegitimate child is required if he/she has reached the age of majority. The consent may be contained in a separate instrument duly notarized."
