Do I need to file a New York State tax return? How do I know if I am a resident of New York State for income tax purposes?Proof of residency must show applicant's address (not P.O. Box or in care of a third party) and include the applicant's name. I declare that I intend in good faith to reestablish my domicile in the United States no later than the date of spouse's admission into the US. Changing domicile requires two important steps: (1) establishing a new domicile; and (2) severing the connection to the old one. 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.