Can different users log into 2 different companies at once in Multi User mode?

Hi there, Digimago.

Yes, the multi-user mode support access for two different company files with two licensed users at the same time. Also, it allows three licensed users access one company file at the same time. 

For future references, you can check on these articles: 

• Features Available And Tasks You Can Perform in Single or Multi-user Mode.
• Host Your Company Data File in Multi-user Mode.

Feel free to get back to the Community team if you have more questions. Have a good one!