How to write a resignation letter that's effective immediately? Learn how to write a short notice resignation letter with this stepbystep guide, template and examples of formal resignation.In the first sentence, clearly state your intention to resign and that your resignation is effective immediately. Use one of our resignation letter templates. Craft your immediate resignation letter with ease using our expert tips and samples to ensure a smooth transition from your job. Simply explain why you're leaving and the date of your departure. "Many people write resignation letters with too much detail," McClellan says. "A resignation letter should be short and to the point. (For example, "I regret to inform you that I will be resigning from my position, effective immediately. Employers may also want to consider the impact an immediate separation would have on remaining employees.