Hello there, 

The number of users you can give access to your company depends on the plan that you have. For now, the system can only invite up to 5 billable users and 2 accountants. For more details, you can click here. 

To give access to your users, you can follow these steps: 

1. Go to the Gear icon and select Manage users.
2. At the upper-right, click Add user.
3. Select the user type and click Next.
4. Set up the user and enter the email address. 

Let the user go to their email to accept the invite. Feel free to visit this page for more information about user roles and access rights in QuickBooks Online.

Keep me posted if there's anything else that you need help with. Have a good one!