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. A) Complete an Affidavit of Support form and; b) Gather evidence of their finances and other supporting documents (See Step 5).If you are applying for a family preference visa, you will need to file Form I-130, Petition for Alien Relative, and Form I-864, Affidavit of Support. If the consular officer determines that your fiancé does not meet the financial requirements, you might be asked to submit an Affidavit of Financial Support. Step 3: File an Affidavit of Support. Is the Affidavit of Support the only form they would fill out? Children under 14 years of age are not required to go to the interview. Another form called DS-156 needs to be filled out. Petition Filing: The U.S. citizen must file Form I-129F, Petition for Alien Fiancé(e), with the United States Citizenship and Immigration Services (USCIS). You must also submit an affidavit of support for your parent, referred to as the I-864 form.