If a child born out of wedlock wants to follow his father's family name, he needs to pay a certain amount of social support fee first, and take the child's birth medical certificate, the household register of both parents, ID cards and other relevant materials to the public security organ to register. Just follow your father's surname when you register. Because illegitimate children do not conform to China's family planning policy, according to China's laws, citizens who do not conform to the provisions of Article 18 of this Law to have children shall pay social maintenance fees according to law. If the social maintenance fees that should be paid are not paid in full within the prescribed time limit, a late fee shall be charged in accordance with the relevant provisions of the State from the date of arrears; If it still fails to pay, the family planning administrative department that has made the decision on collection shall apply to the people's court for compulsory execution according to law.
 Legal basis
 Article 41 of the Population and Family Planning Law of the People's Republic of China shall pay social maintenance fees in accordance with the law for citizens who give birth to children in violation of the provisions of Article 18 of this Law. If the social maintenance fees that should be paid are not paid in full within the prescribed time limit, a late fee shall be charged in accordance with the relevant provisions of the State from the date of arrears; If it still fails to pay, the family planning administrative department that has made the decision on collection shall apply to the people's court for compulsory execution according to law.