Important information that should be in an internship offer letter. The internship offer letter should include the start and end dates of the internship, as well as the number of working hours per week.Dear (student's name): I am pleased to confirm your acceptance of an internship as (Title) in the (Department Name) with (Organization Name). Yes, a cover letter is necessary when applying for internships. Please find the following confirmation. Before you fill the blanks in on this job offer letter template, ensure you're complying with the law. If you can get in touch with people who work there, ask them. They will be able to tell you how it is better than some document.