How to write a resignation letter that's effective immediately? Learn how to write an immediate resignation letter with our comprehensive guide, including tips, examples, and a customizable template.Formal Resignation Letter Sample. We've rounded up tips and examples for writing a resignation letter that'll help you maintain work relationships long after leaving a company. What It Takes to Write A Great Resignation Letter. Create the perfect resignation letter in 30 seconds with our free AI resignation letter generator. Please accept this letter as my formal resignation. Today will be my last day of work. (For example, "I regret to inform you that I will be resigning from my position, effective immediately. I hope this letter finds you well.