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. This is a sample letter for F-1 and J-1 supporters, showing that they are providing monetary support to students.You will be required to submit a copy of the Affidavit of Support and bank letter or statement to the U.S. Embassy or Consulate with your visa application. This form acts as proof that you are financially capable of managing your stay in the United States. Completing and signing Form I-864 makes you the sponsor. Hi there, I'm struggling with how to fill out the I864 and will be very appreciated if anyone can help me out. A briefly introduce ourselves. 12. Affidavit of Support. This affidavit serves as a commitment from the sponsor to provide financial backing for the student's tuition, fees, and living expenses. This form is a legal contract between you and the U.S. government.