Yes, you have to keep track of which computers have which license but the QB desktop software simply needs a license key that hasn't reached max users. So, I keep a file with the license keys and which computers are assigned to them. In a multi-user environment, as long as you store your company file on a network accessible drive, it is the most affordable solution as long as you aren't going to expand to many more users. I have researched going to the Enterprise version and it is almost twice as much for 5 users than if I just purchase 2 (x3 user) Pro licenses. Mileage may vary, considering you may want Enterprise features, but we didn't so my approach was the most reasonable cost-wise.