Every EIN requires its own payroll subscription in QuickBooks Online. If you're using QBOA and wanted to activate the client's payroll, you will need access their account and activate payroll from there. Here's how:
Click the drop-down list for Go to client's QuickBooks and select the correct account.
Go to the Workers menu and proceed to the Employees tab.
Click Get started and follow the follow the succeeding prompts to activate payroll.