In this article, we share tips for writing a short, simple resignation letter and offer examples for you to reference when creating your own. Learn how to write a resignation letter (and what not to include) and then use our example letters as a guide.This sample resignation letter is available for use on UpCounsel. You don't have to send your resignation letter 30 days before the start of the school year, you have to send it 30 days before your planned last day.