We recommend completing Affidavit of Support forms on a computer or typewriter, with answers typed in CAPITAL letters. Some types of evidence you can share to show you intend to establish domicile include: Opening a bank account.Transferring money to a United States account. Providing proof of domicile in the United States is critical for most people when submitting Form I864, Affidavit of Support. 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). This guide will clarify what domicile is, how to establish it, and the documentation you need for proof of domicile. You must file a separate Form I134 for each beneficiary. Forms and Document Downloads. Typically, in order to claim US domicile, the Affidavit of Support sponsor must be residing in the United States.