Employee shall send a written notification to the supervisor at least 2 weeks in advance of resignation. 2. A comprehensive guide on how to write a 2week notice letter of resignation that will ensure a smooth transition for you and your employer.Start with a two weeks notice letter. This will serve as a formal, written documentation of your intent to leave and your transition timeline. You probably won't have to, but some companies do require a formal letter, so you'll have to check with HR as to whether you need to write one. When To Provide a Resignation Letter. The recommended timeline for providing a resignation letter is at least two weeks prior to your planned last day.