Leaving a job isn't easy. To write a short notice resignation letter, include your position and effective date, explain your reason and express gratitude.Please accept this message as my formal notice of resignation. I am fortunate to have received a long awaited opportunity that I cannot pass up. Please accept this letter as a notice of my resignation. State that you wish to quit and include your final day of work. Learn how to write a resignational letter if you're quitting for personal reasons. To leave your role on a professional note, learn how to write a resignation letter. As a bonus, check out our samples. Due to unforeseen circumstances, I must resign.