Income Tax Withholding Methods (LO 9.2) One of the primary differences between an "old" pre-2020 Form W-4 and a "new" post-2019 Form W-4 is: a. The old form can only be used for independent contractors. b. The new form does not rely on the number of allowances to determine withholding. c. The new form requires the taxpayer to sign the Form W-4. d. The new form does not account for the possibility of child tax credits in determining the proper withholding.