FAQ
Questions about VINs
The ones that come up most, answered without hedging. Nothing here is specific to a particular vehicle — for that, decode the VIN.
Can two vehicles have the same VIN?
Not legitimately. Manufacturers assign sequence numbers from their own World Manufacturer Identifier ranges, and the standard is built so that a VIN is unique for thirty years before position 10 cycles back around.
A genuine duplicate means one of three things: a clerical error, a rebuilt vehicle issued a state-assigned number, or a cloned VIN.
My VIN is shorter than 17 characters. Is it wrong?
Probably not. Seventeen characters became mandatory for vehicles of model year 1981 and later. Before that there was no single standard and manufacturers used their own formats, commonly eleven to thirteen characters.
A shorter VIN is usually a genuine pre-1981 number. It will not decode here, because the NHTSA database this site uses begins at 1981. More in why a VIN won’t decode.
Does a VIN ever change?
No. It is assigned once and belongs to the vehicle for life. Replacing the engine, the transmission, the body panels or the title does not change it.
The one exception is not really an exception. A reconstructed vehicle, or one whose original VIN was destroyed or removed, may be issued a state-assigned identification number. That is a new identifier, not a changed VIN, and it will not decode against manufacturer records.
Can I look up a VIN without having the vehicle?
Yes. The VIN appears on the title, the registration certificate and the insurance card, and any of those will decode.
If you are deciding whether to buy, verify the number against the car itself first. A VIN that came only from paperwork tells you about the paperwork. Where to find the VIN covers the locations.
Why are some fields empty when the VIN decoded fine?
Because they are empty at the source. Manufacturers file VIN decoding information with NHTSA under 49 CFR Part 565, and what they filed is what the database holds. Older vehicles and low-volume manufacturers filed far less detail than a current mass-market model.
Empty fields are shown rather than hidden, so you can tell the difference between a field that was not found and one that was not looked for. Each one carries a note explaining its likely absence. See data sources.
Is a failed check digit always a typo?
Usually, but not always. The check digit is mandatory for vehicles built for the North American market and is not required everywhere else, so a grey import can carry a completely genuine VIN that fails the test.
The decoder offers to proceed anyway in that case, because the specifications are often still returned. How the check digit works has the arithmetic.
Does a valid check digit mean the VIN is genuine?
No, and this is the most common misunderstanding about it. The check digit is arithmetic performed on the seventeen characters. It confirms they are internally consistent with each other.
It says nothing about whether those characters belong to the vehicle in front of you. A VIN copied from another car validates perfectly, which is the whole mechanism behind cloning.
Do you store the VINs I enter?
A decoded VIN is sent to our server and looked up against NHTSA. If it decodes, it is cached with its specification so the same VIN answers instantly next time; if it does not, it is not stored. The stored record is the vehicle specification; it is not linked to you, your IP address or your session.
The check digit validator sends nothing at all and runs entirely in your browser. Camera frames from the scanner are decoded on your device and never uploaded. Full detail on the privacy page.
Is there an API?
Not a public one. The data comes from NHTSA vPIC and the NHTSA recall API, both free and publicly documented, so anything this site does you can do directly against the source. The data sources page names the exact endpoints.
Something not answered here?
The reference guides go deeper on VIN structure, and data sources sets out exactly which databases this site queries and what they do and do not contain.