warning letter a warning letter is a formal document issued by an employer to an employee to address violations of company policies, misconduct, poor performance, or any other unacceptable behavior. It serves as an official notice, informing the employee of the issue and the potential consequences if the behavior continues. The letter typically outlines the specific incident or performance concerns, provides evidence or references to previous discussions, and includes expectations for improvement. Employers use warning letters to maintain workplace discipline and ensure compliance with compan