From the home page screen

• Select the Company Gear (located at upper-corner)
• Select “Switch Company” under Your Company heading
• It will take you to login screen with the following messages:
  Company Selection
  Our records show that you have access to more than one company, or multiple users in the same company.
  QuickBooks Online Companies
  newqbo (example)
  oldqbo (example)
  futureqbo (example)
  Canceled Companies
  Oldco (example)