When filing Form I864, it is important to fill out the form completely and provide all required information with your initial filing. 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.When you sponsor an immigrant family member, you may need to file an Affidavit of Support (Form I-864). Here's what you need to know. Line-by-line guidance for properly filling out USCIS's I-864 Affidavit of Support to sponsor an immigrating family member. 864 Affidavit of support How to fill out the Form 864 immigration Tips. In general, Texas has very few official legal forms. This is why you will not always find a free fill-in-the-blank form for your situation. All child support forms are categorized and linked below as downloadable files. Select the category you need to see the corresponding forms.