On Form I864, petitioners must prove that they have the ability to financially support the visa applicant(s) if necessary. This guide will explain how to prove domicile when filling out Form I-864 ("Affidavit of Support").Consular processing support without the high price tag. If you want to sponsor someone for a family-based green card, you need to provide proof of a U.S. domicile in your Affidavit of Support (Form I-864). There are five stages for application submission. 1. 1. Open the e-District portal and log in. He provided the proof of certified mailing to the Board. Ferrari described his application for a proposed AA in the basement of the residence. To complete Form I864, the petitioner must meet certain requirements. This guide will clarify what domicile is, how to establish it, and the documentation you need for proof of domicile.