If an employee qualifies for exemption from withholding, the employee can use Form W-4 to tell the employer not to deduct any federal income tax from wages. The redesigned W4 form no longer has allowances.We explain the five steps to filling it out and answer other FAQ about the form. Information about Form W4, Employee's Withholding Certificate, including recent updates, related forms and instructions on how to file. The W4 is a federal tax form that employees fill out to tell you how much federal income tax to withhold from their paycheck. First, use the withholding calculator to fill out Form W4 so you don't get a refund or owe any taxes. If an employee wants to claim exemption from all income tax withholding, Form W4 must be completed annually. To access the electronic W-4 feature, you must log into the portal. Employees who work in a locality with state income tax must fill out a withholding form. Learn which state W-4 form your employees must use.