How may I acquire a domicile of my choice? How to fill out the Residence Verification Form Harris Health?1. Enter client and household member information. 2. One of the requirements for Form I864 is showing that you are domiciled in the US. In other words, your principal residence must be located in the US. A person's choice of domicile will determine many of his or her legal rights and obligations. There are several requirements to submit an I864 Affidavit of Support. The proof of U.S. domicile is one of those required documents. Learn how your country of domicile affects U.S. immigration, the difference between domicile and residency, and more. Your domicile is your state of legal residence. It is your permanent home.