If you use your vehicle for businesses purposes it is highly recommended that you look into purchasing commercial auto insurance. The similarities between private passenger auto and commercial auto insurance are many, in fact, the options are almost identical. The difference is that private passenger auto insurance policy will NOT cover you if you are using your vehicle for business purposes. There are some companies that will have an endorsement/option to add business or artisan use onto your private passenger auto policy, but this option is only for light use, such as individuals who are painters, or light construction. There are also some vehicles that will automatically be placed in a commercial auto policy due to their weight or configuration.
The level of coverage & the type of business you are in is what affects the cost/premium of your policy. Also, the driving records of your drivers is goin to be a very important factor in the cost of your policy. Some insurance companies also use credit scores to rate their policies.