How to write a resignation letter that's effective immediately? Dear (name of manager),.Due to unforeseen circumstances, I must resign from my position effective immediately. I am writing to inform you that I will be resigning from my position as (Title) at (Company Name). Please be advised that I am resigning from my role of Product Manager with Bradley Org. My final day in the office will be August 31, 2023. Like any formal letter, you need to start with the date and your contact details – the most suitable being your phone number and personal email address. (For example, "I regret to inform you that I will be resigning from my position, effective immediately. People have mixed opinions on just how much detail you should provide to your employer about why you are leaving, and what your new job will be. Please be advised that I am resigning my position with immediate effect. Regards,.