Like all tax forms and publications, Form W-4 is downloadable free of charge at IRS.gov. Simply locate the W-4 hyperlink under the Forms & Pubs header at the agency home page.
While many taxpayers complete the form when they begin a new job and never make changes, TurboTax urges employees to review withholding allowances regularly. Employees that get married, have children or take on an additional job during the year may benefit from completing a new form. It is also helpful to workers who are having too much or too little Federal tax withheld from their pay. The Withholding Calculator at IRS.gov can help to determine the effects of any changes. To adjust the withholding, employees can download and print a new W-4 from the site and submit it to their employers, explains IRS.gov.