Does a son need paternity test when he immigrates to Hong Kong with his father?

The Hong Kong government does not require paternity testing, but requires proof of kinship.

Take the household registration book to the police station where the household registration is located, and the police station can open it after checking the file to determine the relationship. The format is known to the police station. (If the household registration is in a different place, go to the police station where your parents are registered, that is, where you started, and you can find the most original household registration information). If for some reason (for example, you can't find the original household registration information of the police station), you must go to the hospital for paternity test, and then go back to the police station to issue a certificate.