An object of the present invention is to provide a communication system capable of broadcasting and distributing various types of messages. The communication system according to the present invention includes a network operator device (21) disposed in a network (20) managed by a carrier; and a service platform (30) disposed between the network operator device (21) and a plurality of application servers that provide an application service. The service platform (30) transmits, to the network operator device (21), distribution data transmitted from any one of the application servers according to an event notification transmitted from a communication device (10—1), and a distribution policy used to distribute the distribution data. The network operator device (21) distributes the distribution data to a plurality of communication devices (10—1) to (10—3) based on the distribution policy.