Generally speaking, if you are driving a company-owned commercial vehicle, you will be covered by the company's commercial auto insurance policy. However, if you are driving your own personal vehicle for commercial purposes, you may need to purchase a commercial auto insurance policy or a personal auto insurance policy with a commercial endorsement.
It's important to carefully review the terms of your auto insurance policy and/or your employer's commercial auto insurance policy to determine what coverage is provided and what additional coverage you may need.
