Good day, floordoctor. I appreciate your time in reaching out to us about your question regarding Box D of the W-2 forms.
To clarify, Box D is used to enter a control number that some payroll departments use to uniquely identify each employee's W-2 form in their system.
Please know that QuickBooks Payroll does not provide or populate anything in Box D since it is not a required field by the IRS. The control number box is optional. You can read more details about this here: General Instructions for Forms W-2 and W-3.
For additional guidance on filing year-end tax forms through QuickBooks Online Payroll, I'm also sharing these helpful articles:
Don't hesitate to reply or visit us again if you have any other questions about W-2s or filing year-end tax forms, floordoctor. I'd be happy to explain further and make sure you have the resources you need.