When an employee makes an informal or formal complaint, the employer should take immediate steps to stop the alleged conflict, protect involved parties and begin investigations. Under many laws (e.g., Title VII, the Americans with Disabilities Act (ADA), the Age Discrimination in Employment Act (ADEA), the Occupational Safety and Health Act (OSHA), the Sarbanes-Oxley Act, state and local nondiscrimination laws), employers are legally obligated to investigate complaints (harassment, discrimination, retaliation, safety and ethical) in a timely manner. In addition, any appropriate corrective action is required to be taken by the employer to ensure illegal actions and behaviors cease immediately.

Responsiveness to a complaint and an investigation will not only yield the best information and evidence, but it will also enhance both the investigator's and the employer's credibility. Investigations can help the organization identify and resolve internal problems before they become widespread. Given that every complaint has the potential to become a lawsuit, employers should investigate every case in a manner in which it can be presented to a court of law, if necessary. As potentially disruptive as investigations can be, they must be prompt, thorough and effective to ensure everyone's protection.