Whether your company owns a fleet of vehicles or employees occasionally use a personal auto for work, your business should have commercial auto insurance to protect your business. Why? Your business can be held liable for accident damages, even if it occurs in a personal vehicle used for business purposes.
In general, it is not good idea to rely on personal auto coverage for business protection. Personal auto policies typically exclude or provide insufficient coverage for business activities, and they simply do not cover vehicles owned by your business.