Liability coverage under your personal auto insurance policy also typically will not provide coverage if the rental vehicle is driven by someone who is not listed as a driver on the policy, especially those under 21. Some personal auto insurance policies, however, may have provisions for permissive use by others. It's important for both the policyholder and those who may drive their car to understand the specific terms and conditions of their insurance policies.
Rental car companies typically have their own insurance policies, and drivers may opt for additional coverage when they rent a vehicle. However, it's important to carefully read and understand the terms and conditions of any rental car insurance policy, as coverage may vary among companies and may not cover all types of drivers or situations.
To ensure adequate coverage in the event of an accident involving an unauthorized or unlisted driver under 21, it is recommended to discuss coverage options with the rental car company and to fully understand the terms and conditions of any insurance policies that may apply.