A service management system manages use authority for service information, the service information including a content of a service to be provided to a user of a vehicle, the service management system includes a memory configured to store a user ID given for each user of the vehicle and service information set for each vehicle, the user ID and the service information being associated with each other, and a processor configured to unify the use authority for first service information when a plurality of pieces of service information is associated with a single user ID, the first service information being included in each piece of service information.