A communication terminal (10) according to the present disclosure includes: a control unit (12) configured to, in a case of a movement from a communication area formed by the 5GS to a communication area formed by the EPS or a movement from a communication area formed by the EPS to a communication area formed by the 5GS, determine whether or not a communication system forming a communication area at a movement destination can satisfy requirements of services; and a communication unit (11) configured to, when it is determined that the communication system forming the communication area at the movement destination can satisfy the requirements of the services, send a connection request message to the communication system forming the communication area at the movement destination.