Thanks for joining the Community. I'd be happy to get you pointed in the right direction for upgrading your payroll account.
Just to clarify, do you currently have QuickBooks Online Enhanced Payroll and want to upgrade to Full Service Payroll (FSP)? If so, you will likely need to speak with an FSP representative for onboarding. One way that you can do this is from within your QuickBooks account, here's how:
Select Workers on the left navigation menu and choose Employees.
Click the blue link underneath Want to automate your payroll taxes? that says Check out Full Service Payroll.
Press Yes, continue when prompted if you Want to upgrade?.
Schedule a time to speak with a Full Service Payroll Specialist and select Send.
I've included a brief video to serve as a visual reference:
Alternatively, you may wish to call the Phone Support Team to assist you with upgrading your payroll. You can reach them with by calling the phone number at the bottom of the page: QuickBooks Full Service Payroll.
That's it. I believe that this information will have you on the path for upgrading your payroll.