You should fill out a separate invitation letter for each person you are inviting. Learn how to create an invitation letter for a visa application with tips, format guidance, and examples to make the process easier.For a general invitation letter, please provide your name, email and home address, and the title of your session(s) and your paper. An invitation letter from you detailing the dates of the intended visit and a summary of the activities to take place during the visit. To request a letter(s), complete the form linked below. Full Name and Contact Information – The letter should begin with the host's full name, address, and contact details. Please attach your paper (complete or ERF) or doctoral consortium acceptance letter, if applicable. Commonwealth of Pennsylvania. Department of Environmental Protection. How to Write a Guest Speaker Invitation Letter in 6 Simple Steps.