You want to give at least a two weeks' notice. There's no question that you CAN walk out tomorrow without giving notice at all, let alone 120days notice.Learn how to write an immediate resignation letter with our comprehensive guide, including tips, examples, and a customizable template. Concluding Your Resignation Letter: FAQs; Can I resign effective immediately? Can I resign without a notice period? If you were fired, don't sign a resignation letter. If you live in an at-will state, there is no requirement to give any notice for leaving or for your termination. You should be prepared to leave at any time. An emergency resignation letter is a polite letter given to a business or organization that states that an employee must terminate their employment abruptly. An at will employee may be terminated at any time and without cause.