If one of the perks of your job is a company car, then chances are your employer pays to insure that car. In that case, there's no question about which insurance policy will cover an accident. But some companies expect employees to use their own cars when they're out on company business, and if you're self-employed, you may use your car for both business and personal reasons.

This gray area between business and personal car use raises a number of questions about car insurance. When does the company's policy cover you and when do you have to rely on your personal auto policy? If you own your own business, will your personal auto policy cover you or do you need to take out a commercial policy? And what about rental cars on business trips? The answers will depend on your specific situation

Personal car, company business
Most large corporations have commercial policies that cover employees while they're traveling. If you're driving your own car on company business and you get into an accident, then chances are that your own policy will kick in first, but it's also possible that your employer's insurance will pay before your own. Be sure to check with your employer and your insurance agent or company to get the lowdown.
Your employer should know the basics about auto insurance coverage for its workers. Make sure you understand how it works at your company. If you are covered through a company policy, find out from your employer who you should call if there's an accident and carry that information in your car.

Significant driving
If you drive around all day making sales calls, you may want to purchase higher liability limits on your personal auto policy. However, if you get direct compensation from the use of your car — you make deliveries, or use it as a taxi or livery service — then you're going to need extra coverage. You may even need to buy a commercial auto insurance policy. It may be tempting to neglect mentioning this little fact to your agent, but if you ever need to file a claim, your insurance company can deny it if it finds out you misinformed them.

Rental cars
If you're on the road for your company and you have to rent a car, make sure you let the rental-car company know that you're there on business. Include your company's name along with your own on the reservation. That way, if anything happens, the rental-car company will know to contact your employer's insurance carrier

If you're using the rental car for both business and personal reasons, the insurance company may have to determine whether you were on the clock at the time of the accident. If you get into a fender-bender during rush hour, then chances are your employer's insurer will cover it. But if you hit a tree at 3:00 a.m. on your way back from the Sunset Lounge, they probably won't.

If you own your own business and you rent cars all over the country, find out whether your regular auto insurance policy includes coverage for no owned autos. Talk to your agent and explain your situation. In some cases, it may be worthwhile to purchase a "no owned auto" endorsement