Use this form to show they have adequate means of financial support and are not likely to rely on the US government for financial support. A) Complete an Affidavit of Support form and; b) Gather evidence of their finances and other supporting documents (See Step 5).An Affidavit of Support sponsor must be at least 18 years old and must be either a U.S. citizen or a lawful permanent resident. Please sign below and attach copies of your valid photo ID and your Immigration documents when you submit this form. Student's Signature. After you receive your I-20, you will be ready to apply for the F-1 Student Visa, just follow the F-1 Visa Application Instructions. In this video we're going to show you how to complete an i 864 and affidavit of support that is needed as part of the package for an adjustment of status. In this guide, we will explain who needs to complete Form I864, when to file it, and how to fill out Form I864 stepbystep.