What is a VIN?
A Vehicle Identification Number (VIN) is a 17-character code stamped on every car, truck and motorcycle sold in the US since the 1981 model year. No two vehicles share a VIN — it works like a chassis fingerprint.
The three sections of a VIN
| Section | What it encodes |
|---|---|
| WMI — characters 1–3 | World Manufacturer Identifier: who built it and where. WBA = BMW Germany, 1HG = Honda USA, 1FT = Ford truck USA. |
| VDS — characters 4–9 | Vehicle Descriptor Section: model line, body style, engine and restraint system. The 9th character is the check digit. |
| VIS — characters 10–17 | Vehicle Identifier Section: 10th is the model year, 11th is the assembly plant, 12–17 are the production serial number. |
The check digit
The 9th character is a mathematical checksum: every letter is converted to a number, multiplied by a fixed weight, summed and taken modulo 11. If the result doesn't match the 9th character, the VIN has been mistyped or mis-stamped. (European-market cars sometimes ignore the check digit, so a failed check isn't proof of a fake.)
Why no I, O or Q?
I, O and Q are excluded because they are easily confused with 1 and 0 on stamped plates and handwritten documents. If your "VIN" contains one of those letters, it's a serial number or a partial code — not a standard VIN.
What a VIN is not
A VIN identifies what the vehicle was when it left the factory. It says nothing about accidents, owners or mileage — for that you need a history report, and even then only incidents that someone reported. See our honest free vs paid VIN check guide.
Ready to decode? Use the free VIN decoder — no login required.
FAQ
01How long is a VIN?
17 characters for vehicles from the 1981 model year onward. Older cars use shorter serial formats — see the 13-digit VIN guide.
02Where do I find my VIN?
Eight common locations: windshield base, driver door jamb, engine bay, frame rail, and your registration and insurance documents. Full list on the where-is-my-VIN page.
03Can two cars have the same VIN?
No. The serial plus the check digit make duplicates practically impossible; a matching VIN on two different cars is evidence of cloning.