After a trial period expires, you have to buy an Acronx license, if you still want to use the software. On the day of buying your first license, software records a starting point (start on the picture). Your license is active from starting point to the finish point and you can decide between monthly and yearly license plans. Software is usable only in the active period of the license and once it expires you have an option to renew it.
The start and finish points of the first license are furthermore used for billing all additional licenses and modules. In practice, that means that purchase of additional licenses and modules is billed for the period between their point of purchase, to the finish point of the first license bought.
Let’s go through an example of this for easier understanding. Someone buys a standard license. Black line on the picture represents a 100% length of the standard license period (from point of purchase till the expiration of the license). After some time, he notices a useful additional module and decides to buy it. This additional module will now be charged for the period of time that passes from the point of purchase of the additional module till the finish point of the standard license period. In the picture point of purchase is when 30% of the standard license periods has passed, so additional module is charged for 70% of its price.