An image forming system comprises a service providing server and an image forming device. The service providing server includes a managing part configured to manage user registration information with which a service user who uses a service with the image forming device and the image forming device associated with each other are registered, a ticket issuing part configured to issue an application delete ticket to delete an application installed in advance on the image forming device when the service user terminates the service, and a ticket sending part configured to send the ticket to a device which has accessed the service providing server when the access from the service user is detected. The image forming device includes a ticket receiving part configured to receive the ticket from the service providing server, and an application deleting part configured to delete the application based on the ticket.