All new hires must provide the Payroll department with Forms W-4. The amount of employees' federal income tax withholding, and, often, state income tax withholding, is determined by entries on this form. Employees indicate their marital status and the number of withholding allowances on these forms. Employees may also indicate that they're exempt from income tax withholding. Worksheets are attached to assist employees in making these calculations. W-4 forms remain in effect until employees update them. Forms must be signed under penalties of perjury. The IRS updates this form every year. Continue W-4 Form.