There are several "people" in insurance, such as the applicant, the insured and the beneficiary. Parents and their immediate family members can buy insurance for their adult ward as the insured and sign it in person. In your case, if your son is underage, no matter who the insured is, the signature is invalid; If the son is an adult and the insured is also a son, the signature is valid; if the son is an adult and the insured is the father, the signature is invalid. The insurance law stipulates that you must sign in person, which is aimed at this situation. If this situation is found in time, you can go to the insurance company to re-sign.