Every car and light truck model year 1981 or later has a unique vehicle identification number (VIN). The VIN is an internationally standardized 17-character number which is used to identify any vehicle.

VINs are used for many important reasons. For example, service shops use VINs to identify the engine, transmission and brake systems installed by manufacturers so that they can properly service vehicles. Law enforcement agencies use VINs to identify and recover stolen cars and car parts. Auto manufacturers use VINs when they resolve safety recalls.

Characters within a VIN indicate a vehicle's year, make, model, where it was manufactured, and more. VIN decoding is the process of deciphering these details.

The Vehicle Identification Number is also used to access the CARFAX Vehicle History Report. Every CARFAX Report contains important information that can impact your decision about a used vehicle. Some types of information included in CARFAX Reports include:

• Vehicle registration
• Title information, including salvaged or junked titles
• Odometer readings
• Lemon history
• Total loss accident history
• Frame/structural damage
• Accident indicators, such as airbag deployments
• Service and repair information
• Vehicle usage (taxi, rental, lease, etc.)
• Recall information

There are many things a seller may not disclose to you, such as a salvage title, flood damage or an odometer rollback. Any of these and other issues can affect the safety, performance and even value of a used car.

To make it more difficult for you to learn a vehicle's history, the wrong Vehicle Identification Number may be listed in an online vehicle posting or the Vehicle Identification Number may not be provided at all. The vehicle's title documents may be altered too in order to hide potential problems.

Use these tips to protect yourself from fraud as you shop for a used car:

• Get the VIN from the seller or off of the vehicle itself. If the seller refuses to disclose the VIN, that could be a sign that they do not want you to learn the car's history.
• Get the vehicle's history. Ask the seller for a CARFAX Vehicle History Report. If the seller does not provide it, use the VIN to purchase a CARFAX Report at CARFAX.
• Confirm the vehicle's identity. Physically match the VIN provided by the seller to the VINs on the vehicle, the vehicle's title documents, and the CARFAX Report. If any of the VINs do not match, you may want to walk away from the deal.