Line 4 – Enter an "X" if the income and withholding tax are from a form 1099. Line 5 – Enter the Social Security number (shown on the W-2 box "a," or 1099).You may file your withholding returns online at tap.utah.gov. You must include your FEIN and withholding account ID number on each return. Use this tool to estimate the federal income tax you want your employer to withhold from your paycheck. This is tax withholding. Download Form W-4 V: Voluntary Withholding Request from the IRS' website. Discover essential forms for withholding tax. Find important information regarding withholding tax forms from the Indiana Department of Revenue (DOR). To make a change or stop the deduction, complete a new Supplemental.