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. If you have a joint sponsor, they must also complete Form I864.In today's video we are going to be filling out form i 864 the affidavit of support form for the joint sponsor. Most family-based filings require an I-864 when sponsoring an immigrant spouse, child, sibling, or parent. You, the sponsor (petitioner), and the joint sponsor must complete Form I-864. See tips for completing Form I-864. If you have a joint sponsor, the joint sponsor must also complete and sign USCIS Form I-864. In today's video we're going to fill out form i-864 the affidavit of support form together. It is one of the most confusing forms. If you are filing Form I864 as the petitioning sponsor, use our How to Fill Out Affidavit of Support Form I864 guide.