How to Decode a VIN (and What It Can't Tell You)

Every car and light truck sold in the US since the 1981 model year carries a 17-character Vehicle Identification Number. It's the car's fingerprint: it records who built it, where, in which model year, and with what basic configuration. Once you know the layout, you can read most of it by eye, and a free decoder fills in the rest.

Look in at least two places and make sure they match. A mismatch on a used car is a reason to stop and ask questions.

• Dashboard: a plate at the base of the windshield on the driver's side, readable from outside the car.
• Driver's door jamb: the certification label on the door edge or the pillar it closes against.
• Paperwork: the title, registration card and insurance card.
• Elsewhere on the car: many makers also stamp it on the engine, the frame or body panels, and print it on some service records.

VINs never use the letters I, O or Q, because they're too easy to confuse with 1 and 0. If you're typing one in and see what looks like an O, it's a zero.

The first three characters are the World Manufacturer Identifier. The first character alone gives the country or region. A few common ones:

The next two characters narrow it down to the manufacturer and often the division or vehicle type. A car's brand and the country it was built in can differ: plenty of Japanese and German brands build cars in North America, and their VINs start with 1, 2, 3, 4 or 5.

This is the vehicle descriptor section. Each manufacturer decides what these positions mean, so you can't read them without the maker's key. That's what a decoder does: it looks the pattern up in the manufacturer's submissions to NHTSA and returns the model, body style, engine, drive type and safety equipment.

Our free VIN decoder uses NHTSA's vPIC database, the same data manufacturers are required to submit. One honest limit: when vPIC leaves a field blank, that doesn't mean the car lacks the feature. Many makers don't report every option.

The ninth character is calculated from the other sixteen. It lets software spot a mistyped or invented VIN instantly. It's required on vehicles sold in North America.

How it works, in brief:

1. 1Each letter is converted to a number (A=1, B=2 … H=8, J=1 … R=9, S=2 … Z=9; digits keep their value).
2. 2Each position is multiplied by a fixed weight: 8, 7, 6, 5, 4, 3, 2, 10, 0, 9, 8, 7, 6, 5, 4, 3, 2.
3. 3The products are added up and divided by 11. The remainder is the check digit; a remainder of 10 is written as X.

For the textbook example VIN 1HGCM82633A004352, the weighted sum is 311, and 311 divided by 11 leaves a remainder of 3, which matches the ninth character. If one character were mistyped, the check would almost always fail.

The tenth character encodes the model year, which isn't always the calendar year the car was built. The codes skip I, O, Q, U, Z and the digit 0, and repeat every 30 years, so A can mean 1980 or 2010. The rest of the VIN, or simply the car itself, makes it obvious which.

For 2001 to 2009 the codes were the digits 1 to 9, and for 1980 to 2000 the letters A to Y again.

Position 11 identifies the assembly plant, using the maker's own code list. Positions 12 to 17 are the production sequence, which makes the VIN unique. Some low-volume makers use part of this section to extend the manufacturer code.

A decode describes how the car was built. It's not a history. Be careful with any site that implies otherwise.

• Accidents and damage. Not encoded. Paid history reports collect some of this from insurers and shops, and they still miss a lot.
• Title brands (salvage, rebuilt, flood, junk). Check the title itself and the government's NMVTIS (opens in a new tab) system, which lists approved low-cost report providers.
• Mileage. Not part of the VIN. Compare the odometer with service records, and see whether it's in a normal range for the age with our mileage checker.
• Whether recalls were fixed. Recalls are issued for a make, model and year; whether this car had the repair is only known to NHTSA's VIN lookup and the manufacturer. Our recall pages show what was issued, and link to NHTSA's VIN recall check (opens in a new tab) for the repair status.
• Exact options. Trim and packages are often only partly encoded. The window sticker, if the seller has it, is better.
• What it's worth. No free source turns a VIN into an honest value. Be wary of anything that claims to.

1. 1Get the VIN before you visit. A seller who won't share it is a red flag.
2. 2Decode it and confirm the year, model, engine and drive match the ad.
3. 3Check recalls for that model year, then the open-recall status on NHTSA's site.
4. 4Research the model year: complaints by component, safety ratings and MPG on our research pages.
5. 5Run a title and theft check through NMVTIS and NICB.
6. 6Match the VIN on the dash, the door and the title in person.
7. 7Get a pre-purchase inspection by a mechanic you choose.