First ... on the Sch C you will have BOTH the company EIN & your SS# on the form so if you receive income or pay payroll taxes/issue 1099 under either they marry up to the one form.
Next, if you pay your child you can deduct the expense on the Sch C the same way as if you paid anyone else as an employee(W-2) or a subcontractor(1099) making sure to file the proper paperwork for each option timely.
