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).The statutory requirements are: twelve months of physical presence in Virginia (i.e. Download a proof of residency letter template for family members, notarized or non-notarized, tailored for legal use. Document(s) submitted as proof of identity must show your full legal name and date of birth. Use our Affidavit of Domicile form to verify the last home address of a deceased person to speed up the inheritance process.