Comprehensive guide to writing an invitation letter for your US visa application, with free samples and tips. What should the letter say?The letter should include specific details like your relationship with the visitor, the purpose of their visit, duration of stay, and financial arrangements. This template is readily available for download in MS Word, Google Docs, and Apple Pages formats, ensuring compatibility with various word processing software. This letter must detail the applicant's name, reason for the employee's application and business travel and anticipated length of U.S. stay. Mode of public transit, including. Metrobus, Metrorail, local and commuter bus services such as ART, Ride On,. Page letter from their church in the U.S. explaining the purpose of their trip.