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. In today's video we are going to be filling out form i 864 the affidavit of support form for the joint sponsor.If you have a joint sponsor, they must also complete Form I864. You, the sponsor (petitioner), and the joint sponsor must complete Form I-864. See tips for completing Form I-864. This video will help you to fill out I-864 For Joint Sponsor. If you are filing Form I864 as the petitioning sponsor, use our How to Fill Out Affidavit of Support Form I864 guide. 30 The joint sponsor must sign a separate Affidavit of Support, Form I-864. At Alcorn State University, students are required to submit an Affidavit of Support and a bank statement. These documents must not be older than three weeks.