Nanny Tax Forms and Helpful Resources Publication 926 is The Household Employer’s Tax Guide, which provides an overview of federal nanny taxes. W-4 helps you determine how much income tax to withhold. IRS Withholding Calculator helps employees identify their tax withholding to make sure the right amount of federal tax is withheld and to determine whether a new W-4 should be submitted. Schedule H is used to report your federal nanny taxes. Click here for the instructions to this form.