The present invention provides a method, program, server, and wearable device that may generate a virtual code, which is not matched with any other code, whenever a payment is requested. Furthermore, the present invention provides a method, program, server, and wearable device that may conveniently add a device while security is maintained, when a user wants to add a device capable of being used as a payment means. Moreover, the present invention provides a method, program, server, and wearable device that may add and use only an algorithm without changing a conventional process, and may provide a wearable device-based financial transaction.