Thanks for checking this with us, @dave156,

At the moment, QuickBooks does not allow adding negative hours into the employees paycheck. The system uses these hours to calculate the employees compensation for the payroll run.

Instead, you only need to input the actual hours worked by the employee to get the correct YTD amount. Otherwise, if you need to deduct an amount from their pay, set up a deduction item for it.

Here's how:

1. Go to the Workers or Payroll menu, then select Employees.
2. Click the employee's name.
3. Tap the pencil icon in the Pay section. Scroll down on the deductions section, then select +Add deductions.
4. Choose Deduction/contribution.
   
5. Enter the details of the deduction then click OK.

To learn more about this, see the following links about the supported pay types in QBO: Add or change pay types.

Let me know if you have any more questions about this. I'll be right here to guide you with your payroll processing. Have a nice day!