Learn how to write an immediate resignation letter with our comprehensive guide, including tips, examples, and a customizable template. How to write a resignation letter that's effective immediately?Use our immediate resignation letter template to create a personalized letter that allows you to leave your job professionally. Instantly create a Resignation Letter with stepbystep guidance. Resign from your position with this informative letter template. I am writing to announce my resignation, effective in 24 hours. In the first sentence, clearly state your intention to resign and that your resignation is effective immediately. Shortly after they hung up, the president9s personal attorney, Bob.