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.Start with the facts and be direct. Start with a two weeks notice letter. This will serve as a formal, written documentation of your intent to leave and your transition timeline. A basic resignation letter should include the fact that you're resigning and the last day you will work. Use one of our resignation letter templates.