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. Explore why a good resignation letter is important and how to write it, and check out our free resignation letter examples. Below is a sample union resignation letter. You should check your union's constitution and bylaws to see if it is specific to whom a resignation must be sent. Use one of our resignation letter templates. (For example, "I regret to inform you that I will be resigning from my position, effective immediately. Smith, I am writing this letter to formally announce my resignation from my job position effective immediately on August 25. Please accept this letter as my formal resignation.