A system for a dynamic adjustment of expiration date of an authorization key, the system comprising: a security product that will be installed on a predetermined number of computers. The administration key allows a use of the software product on the predetermined number of computers during a predetermined period of time. The plurality of authorization units purchased from a vendor that are the smallest increments of time that a duration period of the authorization key is measured in. The expiration date for all the computers can be updated at any time, depending on the number of computers on which the software is installed at any given time. The administration server determines a beginning and an ending date of a functionality of the authorization key for the security product. The data base receives and stores the beginning and the ending date of the functionality of the authorization key for the security product. The communication means that send the beginning and the ending date of the functionality of the authorization key to the software product. The expiration date of the authorization date dynamically changes when the number of computer on which the product is installed increases or decreases.