How to write a resignation letter that's effective immediately? In the first sentence, clearly state your intention to resign and that your resignation is effective immediately.Here is our sample email to resign with immediate effect. Learn how to write a professional resignation letter with our step-by-step guide, easy to use templates and helpful tips. I have accepted a new role as (job title) at (company name). This sets the tone and leaves no room for ambiguity. State your position on the day of resignation: Always mention the position you held in the office on your last working day. Please be advised that I am resigning my position with immediate effect. Regards,. A resignation letter is a formal written notice stating your intention to leave your job.