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). USC husband can write a Declaration of Intent to reestablish Domicile.Learn how to prove your U.S. domicile for a family visa with our stepbystep guide. Essential documents and tips to ensure visa approval. Instructions: Complete this form to clarify for the Michigan Department of Treasury your domicile for tax purposes. Typically, in order to claim US domicile, the Affidavit of Support sponsor must be residing in the United States. Any item presented to establish proof of residency must include the applicant's name and a Michigan residence address (no P.O. boxes or Mailbox Plus addresses). Use our Affidavit of Residency form to verify your home address for official purposes. 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.