However, you must be at least 18 years of age and have a residence (domicile) in the U.S. before you can sign the Affidavit of Support (Form I-864 or I-864EZ). Much confusion surrounds the need to submit I751 affidavits and how to write them.We explain and provide an I-751 affidavit sample. The K-3 nonimmigrant visa is for the foreign-citizen spouse of a United States (US) citizen. This visa category is intended to shorten the physical separation. I am sponsoring the following family members immigrating at the same time or within six months of the principal immigrant named in Part 3. Personal Information of the Affiants. Full legal names (though for sample templates, placeholders may be used). In certain immigration or visarelated situations, an affidavit of cohabitation may be required to prove the legitimacy of a relationship. There is no minimum age to file a petition for a cr-1 spouse visa.