Even those that require you give a certain amount of "notice" before you quit your current job (two_week notice is standard) often may not provide any formal requirement that you do so by writing a letter of resignation or explain in detail why you're leaving.
What Should My Letter of Resignation Say?. If you're not sure of how to write a resignation letter, that's normal __ it's certainly not an everyday task. Take a look at a sample resignation letter, or a few if you want to explore different options. In our view, the shorter the resignation letter, the better.