When a child reaches school age and has no hukou, his parents should first go to the hukou registration office to register his birth. Parents should apply to the household registration authority and provide the child's birth medical certificate. If the household registration authority verifies that it is true, it shall register the birth of the child and register the information of the child in the parents' household registration book.
If the parents cannot provide the medical certificate of the child's birth, they should provide the paternity test of the child to prove that the child is the biological child of the parents. After examining the paternity test, the household registration authority considers that the paternity test is legal and should register the birth of the child.