How to write a resignation letter that's effective immediately? In the first sentence, clearly state your intention to resign and that your resignation is effective immediately.Learn how to write an immediate resignation letter with our comprehensive guide, including tips, examples, and a customizable template. A simple resignation letter format includes a resignation statement, an appropriate notice period, and an expression of gratitude. I have thus officially registered to vote in the state of Illinois which necessitates my resignation from the MICRC as I am no longer a. I wish you both great success going forward. In the meantime, please let me know if I can assist you in any way during this transition period. Sincerely,. Specify the Termination Date: Clearly state the date when the termination letter is issued and when the termination will take effect. Employers may also want to consider the impact an immediate separation would have on remaining employees.