Purpose: To request domicile verification from a nonrelative who is familiar with the household's situation. 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).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. Documents you will need. 1. Collect all necessary documentation supporting your domicile claim.