The internship offer letter should include the start and end dates of the internship, as well as the number of working hours per week. Sample internship offer letter template.Professionalism: Formalizes the agreement, demonstrating respect and seriousness. Download a sample Job Offer Letter template that you can customize with Microsoft Word® Business Letters If it's an unpaid internship, at a small company I would say this probably isn't suspicious. Failure to complete assignments on time will result in a 2000 rupee monthly penalty deducted from pay. An Internship Offer Letter is written correspondence sent to an intern from an employer offering an internship position.