Form W-4 is an Internal Revenue Service (IRS) tax form that is filled out by employees to indicate their tax situation to their employer. The W-4 form tells the employer the amount of tax to withhold from an employee’s paycheck based on their marital status, number of allowances and dependents, and other factors. The W-4 is also called an Employee’s Withholding Allowance Certificate—Read more at Investopedia. Kagan, Julia. “W-4 Form.” 16 September 2019