Enter the item code and the tax exemption for your group. You must select a separate exemption for each individual. You can use code, line, amount, or a value. Furthermore, you will receive a unique ID for each individual. Enter each individual's TIN in the box and the year(s) when you entered his and hers. To determine an individual's tax exemption for the year, you must first determine her or his taxable income, then add that income to other forms that may be applicable or to forms that may have been used for the taxable year. In the case of a head of household (head of household form for single filers only), the taxable income (taxable income for single filers). The taxpayer who enters his or her own information may determine whether the information submitted is complete and correct. Once the Form W-9 is completed, review each line to make sure it is complete. If any line is left blank, the tax exemption may be based on other information on file. Select the appropriate boxes in the form to make a contribution, determine the total amount, and click the Submit button. The following is the instructions for Form W-9, Request for Taxpayer Identification Number and Certification Find box Use one of the following boxes to enter an identification number.