When is a Company Required to Conduct a Formal Workplace Investigation?

A California employer is required to conduct a formal workplace investigation when it becomes aware of allegations involving:

• Harassment (sexual harassment or hostile work environment)
• Discrimination based on a protected characteristic
• Retaliation for protected activity
• Workplace violence
• Serious policy violations or misconduct

Under the California Fair Employment and Housing Act (FEHA), once an employer has notice — whether through a formal complaint, informal report, or observed conduct — it has a legal duty to take prompt and appropriate corrective action.

A formal workplace investigation is typically required when the allegations, if true, would violate law or company policy.

Failing to investigate can create independent liability, even if the underlying allegation is ultimately unsubstantiated. In California employment litigation, courts frequently focus on whether the employer responded promptly and reasonably once notified.