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.Learn how to write an immediate resignation letter with our comprehensive guide, including tips, examples, and a customizable template. I am resigning from Company effective immediately. These resignation letter templates would help you write yours in no time, and learn how generative AI can help too. A resignation letter should be written at least 30 days prior to the effective date of resignation. In the first sentence, clearly state your intention to resign and that your resignation is effective immediately. In the first sentence, clearly state your intention to resign and that your resignation is effective immediately. The motive was not immediately known, but Rivera said: "This is not terrorism. Texas State released former head basketball coach Danny Kaspar's resignation letter under a public records request from The Associated Press.