What Is the Check Digit in a VIN Number?

A vehicle identification number, or VIN, is a unique code used to identify each vehicle produced by the automotive industry. VINs were standardized to a 17-character format for modern vehicles, and the letters I, O, and Q are excluded to avoid confusion with similar-looking characters. The first few characters identify the world manufacturer, the 4th through 8th characters identify vehicle attributes, the 10th character identifies the model year, the 11th character identifies the assembly plant, and the 12th through 17th characters make up the vehicle serial number. The 9th character is reserved for the check digit.

On Dodge Neons, VIN markings can appear in several places depending on what you are checking. The chassis stamping can be found on the right front strut tower and commonly shows only the last 8 digits, while the full VIN can also be found on the dashboard VIN plate at the base of the windshield, the manufacturer’s door decal, and small factory decals on body panels and bumper covers.

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What Does the 9th Digit of a VIN Mean?

The check digit, found in position 9 of the VIN, is used to validate the VIN and is compulsory for vehicles in North America. This character helps identify transcription errors or mismatched VINs quickly.

The check digit is calculated by converting the VIN letters into their assigned numeric values, multiplying each character by a position-based weight factor, adding the results together, and dividing the total by 11. The remainder becomes the check digit. If the remainder is 10, the correct check digit is X.

• Characters 1 to 3 identify the world manufacturer.
• Characters 4 to 8 describe the vehicle attributes.
• Character 9 is the VIN check digit.
• Character 10 identifies the model year.
• Character 11 identifies the assembly plant.
• Characters 12 to 17 are the vehicle serial number.