Learn how to write a resignational letter if you're quitting for personal reasons. Simply write that you're leaving for "personal reasons" after stating your intent to resign and your last day of employment with the company.A resignation letter should be brief and clearly state the employee's intention to resign and the last day of work. Explicit information about the reasons for your resignation. It sounds like your personal reasons for resigning were listed in the letter. Don't forget to write it out. You don't want to put anything in writing that you'll end up regretting committing to later. Due to unforeseen circumstances, I must resign.