If during the tax year you had a New York City or Yonkers change of resident status, you must complete Form IT-360.1. An I864 sponsor must be domiciled in the United States.Domicile is intended to be permanent rather than temporary, whereas residence means living in a particular locality and requires mere physical presence. Bottom Line: You can have 50 residences but only 1 domicile at any time. You are technically a resident wherever you live. Domicile refers to the place you call home permanently. Your domicile is important for legal purposes such as paying taxes, voting, and claiming benefits. In this article, we'll explain how to prove US domicile as part of your Affidavit of Support so you can successfully sponsor a family member for a green card.