There isn't really a limit unless you are on a Sage Accountant Network license copy.  It is easy to go back and forth between companies especially if you have the same login info as there is a setting to automatically login when switching companies.  You can also have multiple companies open at the same time making easy to go back and forth.  [email protected] 

This is the information I needed -Thank you! 

This is the information I needed -Thank you!