I'm here to ensure you'll get the right support to check your prior tax payment amounts. This way, you'll be able to set up your payroll account and start paying your employees using QuickBooks Online Payroll (QBOP).
When you enter your payrolls from earlier years, there will be small differences from what QuickBooks expect. To resolve the rounding of tax amounts, I'd recommend contacting our QuickBooks Online Support team. They can verify your account and can walk you through in completing your payroll setup.