Hello there, tmullen.
If taxes are already paid for these paychecks, then I'd suggest contacting one of our Payroll Support Specialists. They have more resources available to make the corrections.
Here's a link where you can get our contact information: https://payroll.intuit.com/support/contact/?infosrc=qs&service=64
Note: Once the correction is done for the 2017 paychecks, you'll have to amend the forms. Since QuickBooks Online doesn't support amended forms, you can use the Payroll Tax and Wage Summary report for your reference.
Here are the steps:
- On the left panel, click Reports.
- Type Payroll Tax and Wage Summary in the search box.
- Select the Date Range, and click Run Report.
If you have any other questions or concerns about QuickBooks, please let me know. Thanks.