An elevator system comprising: a plurality of destination floor reception terminal devices to output, when an operation key corresponding to a floor of a destination floor of an elevator is operated, operation key information corresponding to the operation key, to convert the operation key information which is output into floor information which is used for a registration of a destination call by using information for conversion as prescribed, and to generate and send a destination call registration request which includes the floor information whereto the operation key information is converted, and which requests the registration of the destination call; and an elevator control device to receive the destination call registration request from each of the plurality of destination floor reception terminal devices via a communication channel, and to register the destination call in accordance with the floor information which is included in the destination call registration request, characterised in that the elevator control device includes a control side storing unit to store the information for conversion, and a control side communication unit to send the information for conversion which is stored in the control side storing unit to the plurality of destination floor reception terminal devices via the communication channel, and wherein each of the plurality of destination floor reception terminal devices includes a terminal side communication unit to receive the information for conversion from the elevator control device via the communication channel, a terminal side storing unit to store the information for conversion which is received by the terminal side communication unit, a terminal side operation key information output unit to output the operation key information when the operation key is operated, and a terminal side data conversion unit to convert the operation key information which is output by the terminal side operation key information output unit into the floor information in accordance with a prescribed conversion rule by using the information for conversion which is stored in the terminal side storing unit, to generate the destination call registration request which includes the floor information whereto the operation key information is converted, and to send the destination call registration request which is generated to the elevator control device via the terminal side communication unit. a plurality of destination floor reception terminal devices to output, when an operation key corresponding to a floor of a destination floor of an elevator is operated, operation key information corresponding to the operation key, to convert the operation key information which is output into floor information which is used for a registration of a destination call by using information for conversion as prescribed, and to generate and send a destination call registration request which includes the floor information whereto the operation key information is converted, and which requests the registration of the destination call; and an elevator control device to receive the destination call registration request from each of the plurality of destination floor reception terminal devices via a communication channel, and to register the destination call in accordance with the floor information which is included in the destination call registration request, characterised in that the elevator control device includes a control side storing unit to store the information for conversion, and a control side communication unit to send the information for conversion which is stored in the control side storing unit to the plurality of destination floor reception terminal devices via the communication channel, and wherein each of the plurality of destination floor reception terminal devices includes a terminal side communication unit to receive the information for conversion from the elevator control device via the communication channel, a terminal side storing unit to store the information for conversion which is received by the terminal side communication unit, a terminal side operation key information output unit to output the operation key information when the operation key is operated, and a terminal side data conversion unit to convert the operation key information which is output by the terminal side operation key information output unit into the floor information in accordance with a prescribed conversion rule by using the information for conversion which is stored in the terminal side storing unit, to generate the destination call registration request which includes the floor information whereto the operation key information is converted, and to send the destination call registration request which is generated to the elevator control device via the terminal side communication unit.