How Can I Prove U.S. Domicile? In this post, we'll explore examples of proof of US domicile and the documents required to establish proof of domicile.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). Learn the meaning of domicile in U.S. immigration and its implications. Understand its relation to the visa application process and immigrating to the U.S.. You are required to obtain the original or certified copy, and one photocopy (with the exception of your passport and photographs) of the following documents. This guide will clarify what domicile is, how to establish it, and the documentation you need for proof of domicile.