An authority delegate system, including a server system which provides a service to a device having an application, and an authorization server system which performs authorization processing to delegate user authority in the service to a usage source of the service, includes a management unit, and a providing unit. The management unit identifies authority of the application, in accordance with having received a request to register the application as the usage source, and manages the identified authority, and an identifier of the application, in an associated manner. The providing unit provides the service, in a case where an authorization operation has been performed to permit delegating of the user authority to the application transmitting a request to use the service, and an authority which the application uses is included in authorities associated with the identifier of the application.