The Vehicle Identification Number (VIN) of a vehicle is a unique code assigned to the car by its manufacturer primarily for identification and registration purposes. The number can be decoded to tell specifics about the vehicle, such as make, model, year, body style and engine size. By knowing this information insurance companies can tell what options your vehicle came with as well as know the history of the car.

A VIN is typically needed by an insurance company to properly transmit your insurance information to the state's DMV database. If the VIN is used to find out the history of the vehicle and it shows that the car has a salvage title or has been totaled or stolen in the past it could possibly change your rates if this was not told to the insurance company beforehand.

Since insurance companies differ on their rating systems you would have to contact your state's insurance regulatory body to find out how a particular insurance company determines its rates since this information must be filed with this government agency.