QB Issue Resolution:

users are determined by you, and the associated rights they have concerning access to QBO

QBO can be accessed by anyone from any computer anytime as long as they have the login and password (assumes they have internet access and QBO servers are up)

Resolution for Issue 'DO I NEED DIFFERENT USER TO EACH COMPUTER?' available: Yes (Solved).
Source: Intuit Community forum.

DO I NEED DIFFERENT USER TO EACH COMPUTER?: this issue or error code is a known issue in Quickbooks Online (QBO) and/or Quickbooks. Support for this issue is available either by self-service or paid support options. Experts are available to resolve your Quickbooks issue to ensure minimal downtime and continue running your business. First try to resolve the issue yourself by looking for a resolution described below. If it is a complex issue or you are unable to solve the issue, you may contact us by clicking here or by using other support options.

Support for Quickbooks
Quickbooks Repair Pro will resolve it efficiently and affordably. Guaranteed resolution of your issue, or you pay nothing!

Error Recovery for Quickbooks [Canada]
E-Tech is the #1 Quickbooks data migration and Conversion service provider.

Get 50% off Quickbooks Online

Click Here for 50% off!

Additional Support Options: