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. By signing the Affidavit, the Financial Sponsor agrees, and promises to provide support for the student.Much confusion surrounds the need to submit I751 affidavits and how to write them. We explain and provide an I-751 affidavit sample. The following evidence of ability to provide financial support must be submitted with this completed affidavit: 1. 1. Talk to the person immigrating to the US. The person for whom you write an affidavit should be someone you know very well. Affidavit. 1. The Affidavit must be fully and properly completed. (Print in ink or type, in. English). 2. Instructions on the website to fill out the order form and mail it in. I have authorized the release of my supporting financial documents to verify that the promised financial resources are available to me.