What a VIN is
A vehicle identification number is a 17-character code assigned by the manufacturer. In the United States the format is set by federal rules (49 CFR Part 565) and has applied to cars and light trucks since the 1981 model year. Before that, manufacturers used their own formats and lengths, which is why older classics have shorter numbers that a modern decoder can't read.
No two vehicles built within 30 years of each other share a VIN. It stays with the car for life: through every owner, every state and every title.
Why it matters when you buy
- State title and registration records are filed under it.
- Insurers report total losses against it.
- Manufacturers and NHTSA track safety recalls by it.
- Police and insurers record thefts by it.
- Commercial history reports are built by matching records to it.
So if the VIN you check isn't the VIN on the car, every check you run is about a different vehicle.
Where to find it on the car
| Location | What to look for |
|---|---|
| Dashboard | A metal plate at the base of the windshield on the driver's side, readable from outside. This is the most common place to check. |
| Driver's door jamb | The certification label on the door edge or pillar. It shows the VIN with the build month and weight ratings. |
| Engine bay and frame | Many vehicles have the VIN or part of it stamped on the firewall, frame or engine block. Locations vary by make. |
| Other labels | Some vehicles carry VIN labels on major body panels and parts, part of federal theft-prevention rules for certain models. |
Photograph the dashboard plate and door-jamb label on your phone. You'll want them when you compare the paperwork.
Where to find it in the paperwork
- Title certificate. The document that proves ownership. The VIN, brand notes and recorded mileage all appear here.
- Registration card. Issued by the state, usually kept in the glovebox.
- Insurance card or policy. The insurer's copy of the VIN.
- Service records and the online advert. Many dealers list the VIN in the listing; private sellers often will on request.
Make sure every copy matches
Compare all 17 characters, not just the last few. Read them out slowly. The most common honest mistakes are swapped characters and look-alikes like 8 and B, 5 and S, or 2 and Z. The letters I, O and Q never appear, so if you think you see one it's a 1 or a 0.
Real warning signs include:
- A dashboard plate that looks loose, scratched, re-riveted or glued.
- A door-jamb label that is missing, torn or obviously newer than the surrounding paint.
- A title VIN that differs from the car by even one character.
- A seller who won't let you see the dashboard plate or door jamb.
Any of these is a reason to walk away until it's explained in writing. A VIN that has been altered to hide a stolen car is called a cloned or re-tagged VIN; see the stolen vehicle check guide.
Once you have it
Run it through the VIN decoder to confirm the check digit and model year, read the 17-position guide if a field looks odd, then move on to the free recall and theft checks.