IRS FORM W-9 is a request for a taxpayer identification number. Individuals use the form to provide their taxpayer identification number to businesses or individuals who will pay them income during the tax year.
FORM W-4 EMPLOYEE’S WITHHOLDING CERTIFICATE
You must give all new employees this form. Each employee must fill out the form and return it to you. The W-4 shows their filing status and how many withholding allowances they claim. You keep the original W-4 and send a copy to your payroll provider and/or CPA.