Every resigning employee shall be urged to indicate in the Resignation form the reason for leaving. If you want to keep it professional you should avoid the detailed laundry list.How to write a resignation letter that's effective immediately? Yes. Illinois is an "employment at-will" state, meaning that an employer or employee may terminate the relationship at any time, without any reason or cause. My employer asked me to sign a resignation letter. I will go over a step-by-step resignation template letter you can use, how to structure it and provide examples of resignation letters. Stay Focused: Avoid delving into unrelated or personal issues in the termination letter. Add contact details, company name, and date. It helps you resign professionally, promote a smooth transition, and put your health first. But the purpose of a resignation letter (at least in the US) is just to establish that you're leaving voluntarily, for legal reasons.