To write a short notice resignation letter, include your position and effective date, explain your reason and express gratitude. Say "personal reasons" as a reason for quitting a job.I do not wish to explain in detail to my employer my reasons for leaving the job. Learn how to write a short notice resignation letter with samples. Find a solution to the challenge of resigning on short notice. "The letter should be a factual statement of departure, without emotion, anger, threats, or reasons for leaving," Caprino says. Simply write that you're leaving for "personal reasons" after stating your intent to resign and your last day of employment with the company. Name, position held, resignation statement, and last day to work are all necessary for a resignation letter.