The difference between retirement and quitting is that you would typically need to reach a certain age and be with the company a certain length of time. A notice of intent to retire on a specific date is essentially a resignation letter.A retirement letter has similarities to a letter of resignation because they both state your decision to leave a job. Both possibilities involve leaving your job; however, there are some benefits you're entitled to get when you retire instead of resigning. A resignation implies future activity. Friends, colleagues, and students will want to know what is next for me. A retirement resignation letter allows your company to plan for your absence and begin the hiring process for your replacement. If you decide to move after you have retired, we need to get in writing the new address information. A resignation letter provides notice that you will leave a company. Give your employer at least two weeks' notice.