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.
@BRC is correct! Allow me to share additional information on how you can update your employees social security number.
Let me know how it works on your end. I'm always here to lend a hand in making your tax information is correct.