In many states, the car owner's auto insurance provides primary coverage when someone else is driving the vehicle, as long as they have permission from the owner. However, if the car is being used for commercial purposes and the driver only has a personal policy, there may not be sufficient coverage. It's also important to consider the driver's license status, as insurance likely won't cover someone who isn't licensed. If someone lives at your house full-time or frequently drives your vehicle, they should be listed on your policy.
Permissive use is when you give someone who is not on your insurance permission to borrow your car. In this case, the driver is covered by your car insurance even though they aren't on your policy. However, some insurance policies may require excluding certain drivers for various reasons. If a driver is excluded, coverage won't be available for them driving your car, so you shouldn't give them permission to do so. If someone has permission to drive your car and gets into an accident, your insurance will act as the primary insurance policy for any damages that they caused. However, if the damages exceed your policy limits, any other applicable policies like the driver's own car insurance will be considered excess or secondary insurance. It's important to note that adding a new driver to your insurance policy can impact your premiums.