A retirement letter is a letter you can submit to your employer to formally announce your retirement and your intention to resign from your position. Learn how to craft a heartfelt retirement letter for your Burger King career.Express gratitude and leave a lasting impression. In this blog post, we'll review some guidelines for writing a retirement letter and offer tips for getting them out before the deadline. Context: I'm senior director for midsize software firm. I'm giving notice on Monday, and last day with the firm to be Sept 13. In the body of the letter, state your intended retirement date (your last day) and your thoughts on a transition plan. In the opening paragraph, make it clear that you are retiring. I am retiring, early, in fact I have had an evil plan in the works for some time. A retirement letter is a type of resignation letter, but the main difference is its purpose.