While you are in the United States, you may want to invite your friends or family members to visit you. If the purpose of their visit is for a short period of travel, they will most likely apply for a B-2 visitor visa for the trip. Students and alumni may request a letter of invitation using the from below. At the time of the visa interview, prospective visitors will also need to demonstrate financial support for the trip, intension to return home, produce travel-size photo, and pay all applicable fees. Requirements may vary per country. Learn more at Travel.State.Gov.