Each inFlow On-Premise license (no matter if it’s Regular or Premium) enables editing for one editing user at a time. So the answer to your question would be “How many users are planning on editing data at the same time”?
For example, if you need 3 users to work in inFlow at the same time editing data, then you’ll need at least 3 licenses. Users who only need to view the data but not edit do not require a license (they can just download the free edition and connect via multi-user mode).
If the users don’t need to edit data at the same time, then you can just get however many licenses that will be in use at a time. As an example, if you’ve got a staff of 6 users, but only 2 ever need to edit data at a time, you would only need 2 licenses.The first 2 users to log in to the program would get the licenses, and the rest would log in as Free edition, read-only mode. When any of the first 2 users close the program, that would free up the license for use for the other users.
You can also specify certain editions per user, for example you can set it up so that the accounting staff would only use free no matter if they were the first to log in. For more info on how to set that up please see here.
You can also mix and match licenses (having a mixture of Premium/Regular), and it all depends on what features you need for your users. You can check out the differences across Premium/Regular here.
If you have any other questions or concerns about licensing please do let us know!