There is disclosed a licensee notification system for implementing a software sales system wherein license information for converting to executable form software that is presented to a user in non-executable form is communicated to the user from a management center on condition of payment of a charge, and the software is converted into executable form at the user terminal using this license information. The subject of the licensee notification system is software that decides whether or not the correspondence relationship between user identification information and signature information stored in the license file is legitimate, and, if it is legitimate, displays the user identification information to the user before starting proper operation; or, if it is not legitimate, does not start proper operation. The licensee notification system is constituted by connecting the management center and user terminals by communication circuits. If license information is requested from the user terminal, the management center transmits license information combining in integral form the user identification information identifying the user and conversion information for converting the software to executable form. The user terminal enables the software using the conversion information contained in this license information and writes user identification information and signature information whose content is determined in accordance with the content of the user identification information to a license file that is referred to when this software is operating.