As soon as you get their application, check what they entered against their Social Security card, which you are required to confirm.
If you didn't do that, or you entered the SSN wrong for other reasons, then edit the employee and change the SSN.
Pleased to have you here, @jw01.
If you're referring to the information of your employees in ViewMyPaycheck, you may check out this article: ViewMyPaycheck: QuickBooks Desktop for Windows FAQs.
Let me know how it works on your end. I'm always here to lend a hand in making your tax information is correct.