All ClearCalcs licenses work on a floating concurrency model - i.e., they are 'shared' by default.
Only as many users may be logged in and working on a project in ClearCalcs at any one time as you have subscribed shared licenses. So for example, if you have one shared license, one person may use the software at a time. We only measure users actively working on projects and calculations, so IT and billing administrators do not count towards your limit.
You may add as many users as you would like to ClearCalcs, so everyone still gets the benefit and security of their own account and projects.
If too many users log in at once, you don't need to worry - we'll give a friendly warning that you're over your limit, and if this happens repeatedly we may show upgrade options or contact you to discuss subscribing for additional licenses.