In this article, we discuss how to write a conformational letter, look at sample templates for formal and informal confirmation letters and share some tips. Award Letter Template.A proof of income letter, otherwise known as a salary verification letter, is an official document that proves you're currently employed and earning a salary. Congrats on completing the probation period! Fill out all forms completely and legibly. If they are incomplete or unreadable they will be returned to you UNPROCESSED and UNREGISTERED.