If I claim a 1099 on an employee, do I need their social security number?

Answer 1

Employees get W-2s.
Independent contractors get 1099-Miscs.

You cannot arbitrarily pick which form to use.

For an employee, you were supposed get their SSN when you hired them. For a contractor, you were supposed to get their SSN *before* you paid them. (Because if you didn't get their SSN, you were supposed withhold 28-30% for federal taxes and send them in to the IRS.)

Answer 2

Yes