Learn how to create an effective affidavit of support with our detailed guide and sample. 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.Much confusion surrounds the need to submit I751 affidavits and how to write them. We explain and provide an I-751 affidavit sample. Family support: Sponsor's certification and copy of bank statement. Name and relationship of family member(s):. Verify statements for legal matters and business transactions using our Illinois general affidavit form template. If you would like to see an example letter to show what it should contain, please send an email request. Please be aware that forms will be displayed in a NEW browser window. Affidavit For Final Tax Period.