What should the letter say? An invitation letter from you detailing the dates of the intended visa and reason for visa.You can either choose to fill in the blanks on the template (it can be filled in online) or create your own letter using the template as a guide. The Letter of Invitation will be emailed to the graduate, who can then forward it to her or his parents for use in documenting their visa request. Full Name and Contact Information – The letter should begin with the host's full name, address, and contact details. Note: This is a sample only. The letter must be typed on department letterhead. Comprehensive guide to writing an invitation letter for your US visa application, with free samples and tips. A foreigner traveling to the United States to conduct temporary business must have a visitor visa (B) unless qualifying for entry under the Visa Waiver Program. Complete the Invitation Letter form.