Your resignation letter won’t be a novel-length saga, and since you’re leaving the company, there’s no need to argue a case or request anything from your audience. So at all times—no matter how tempting it may be to do otherwise—keep your message concise and positive.
Less is more: Keep detail and volume to a minimum. Unless your departure breaks contract, you do not have to ask permission to leave. So don’t. Announce that you’re leaving, explain why if you wish, and end your message.
Check your contract: If you’re legally bound to the company by an ongoing contract, a simple letter of resignation won’t let you off the hook (no matter how well written it may be). You’ll need to talk to your employers and HR department in person to untangle this thorny issue.
Be kind: If you’re leaving because you dislike something about the company that your readers can’t change, be gracious and diplomatic.
Be honest: On the other hand, if you’re leaving because of something that can and should be changed, say so. An explanation for your reason to leave can help a struggling company interested in change and growth. Also consider that if you miss an opportunity to share this information, you may be haunted by this decision later. Could you have helped your former employers learn from their mistakes? If you aren’t/weren’t being paid fairly, for example, now is the perfect time to share this fact—just remember to support your claims with research.
Say thank you: Share the things you enjoyed most about the job, and thank your employers for this opportunity. Even if you detested your position, there must be some positive aspects.