How to make a retro payroll payment on separate check

Hello, davis-wanda-comc. 

I'll give steps on how you can do this.

You can process a separate paycheck for the same period by following these steps:

1. Go to Payroll > Employees.
2. Select the Run payroll button.
3. Choose the Pay Schedule and find the employee you want to pay.
4. Confirm the pay period and check date. Then, click the Create another check link.
5. Enter employee compensation, including any salary adjustments, vacation or sick hours, and other pay types.
6. Select Preview Payroll, and then select Submit payroll. If creating a paper check, hand write or print the check and give it to the employee by the check date.
7. Select Finish payroll.

For reference, you can check out this article: Create Unscheduled Payroll Check.

I'd also like to add this guide to help you with the year end task: Year-end guide for QuickBooks Online.

Please feel free to comment below if there's anything else you need. I'll be around to help you out some more. Take care and stay safe!