How to Read a VIN: Decode Every Digit

Every road vehicle built since 1981 carries a 17-character Vehicle Identification Number. It is not a random serial. Each position, or group of positions, carries a specific fact about the car. Once you know the layout you can read a lot from the number alone.

The three blocks

A VIN splits into three parts.

• Positions 1 to 3, the World Manufacturer Identifier. These say who built the car and where. The first character is the region, for example 1, 4 and 5 for the United States, J for Japan, W for Germany, S for the United Kingdom. The next two narrow it to the maker and vehicle type.
• Positions 4 to 9, the Vehicle Descriptor Section. These describe the model, body style, engine and restraint system. Position 9 is a check digit, a calculated value that confirms the rest of the VIN is internally consistent.
• Positions 10 to 17, the Vehicle Identifier Section. Position 10 is the model year. Position 11 is the assembly plant. The last six are the sequential production number, unique to that unit.

The letters that never appear

A valid VIN never uses I, O or Q. They look too much like 1, 0 and 9, so the standard leaves them out. If you see one of those letters, the number is either mistyped or not a real VIN.

The check digit

Position 9 is math, not description. Each character is given a value, each position a weight, and the weighted sum modulo 11 must match the check digit (with X standing for 10). A VIN that fails this test has a typo or has been altered. It is the fastest single test of whether a number is genuine.

The model year letter

Position 10 encodes the model year on a repeating cycle. Letters run A for 1980 through Y for 2000, then numbers 1 through 9 for 2001 to 2009, then the letters start again at A for 2010. Because the cycle repeats every 30 years, the year letter is read together with the rest of the VIN and the car's apparent age, not on its own.

What a VIN does not tell you

The VIN describes how the car was built. It does not carry mileage, accident history, title status or ownership. Those come from records tied to the VIN over the car's life, which is what a history lookup pulls together. The number is the key that links them.

Quick checks before you trust a VIN

• Count the characters. Exactly 17, no more, no less.
• Confirm there is no I, O or Q.
• Check the year letter against the car's apparent age.
• Confirm the VIN on the dashboard plate matches the door jamb sticker and the title.

A mismatch between any of those is worth stopping for.