In the opening paragraph, make it clear that you are retiring. Your resignation date should be your last day of paid service.The effective date of your retirement should be the day following your resignation. In the body of the letter, state your intended retirement date (your last day) and your thoughts on a transition plan. Essentially, it's an official notice from an employee, communicating their decision to retire from their current role within the organization. My reason for leaving is (check appropriate box):. Resigning from County service for the following reason(s):.