The VIN, or vehicle identification number, is a unique 17-digit code that is assigned to each new car when it is made. The code uses both numbers and letters to help track vehicle histories.
The VIN number is found in multiple locations in the car such as the driver's door, the firewall, instrument panel, steering column, or left-hand inner wheel arch as well as in any vehicle documents.
From the VIN you can determine what country a car was made in, which company made it, and details about the car's systems. The ninth digit of the VIN is a verification digit that is calculated based on the first eight to ensure the VIN is legitimate.
When buying a used car, you can request a vehicle history report. Each time the owner changes, the car is registered at a Department of Motor Vehicles, insurance or warranty claims are filed or other significant events occur they are added to the car's history based on the VIN.
All of the VIN numbers in the car should match, unless parts have been replaced. Repairs may have been made using non-standard parts or even parts stolen from other vehicles.
VIN numbers appeared in cars starting in the 1950s, but it wasn't until the 1980s that the the U.S. Department of Transportation required VINs and standardized them in the current 17-digit form.
