How to write a resignation letter that's effective immediately? Learn how to craft a professional resignation letter without notice with our guide.It's time to quit the job, and you're not giving two weeks' notice. Here's how to politely write a resignation letter, effective immediately. With or without a contract a 2-week notice is customary and polite. Learn how to write a short notice resignation letter with this stepbystep guide, template and examples of formal resignation. Unless you are a some sort of convict labor, you really don't need to do anything. Most twoweek notice letters have a resignation date effective 10 business days (two full weeks) from the date of your letter.