You must have QuickBooks Pro or QuickBooks Premier if you plan to use QuickBooks in a multiuser environment where more than one person can access the company file at once. A maximum of five users can access the QuickBooks company file simultaneously; however, there is no limit to the number of users who can access the company file at different times. Each workstation must have a licensed copy of QuickBooks installed, and have access to the server where the company file is stored. Another alternative for a multiuser office is QuickBooks Enterprise Solutions, which allows up to 10 simultaneous users.
Set Up QuickBooks in a Multiuser Office