A terminal device (10) includes: an information storage unit (102) that stores registration information for establishing a wireless communication connection with an electrical treatment device (20); a detection unit (104) that detects a beacon signal emitted from the electrical treatment device (20); a determination unit (106) that determines, on the basis of the registration information stored in the information storage unit (102) and the beacon signal detect, whether the electrical treatment device (20) includes an unregistered electrical treatment device (20) not registered with the terminal device (10). In a case where the unregistered electrical treatment device (20) is included, the determination unit (106) further determines, on the basis of the beacon signal detected, whether the unregistered electrical treatment device (20) includes registration information of a device other than the terminal device (10). The terminal device (10) further includes a notification unit (118) that provides notification on information including a solution for an error when the electrical treatment device (20) not registered with the terminal device (10) includes the registration information of the device other than terminal device.