What Is a VIN Number?

A VIN — Vehicle Identification Number — is a unique 17-character code assigned to every road vehicle manufactured since 1981. It is the vehicle's fingerprint: no two vehicles anywhere share one, and it stays with the vehicle from factory to scrapyard, no matter how many owners or license plates it passes through.

What the number encodes

The 17 characters are not random. Federal standard 49 CFR Part 565 divides them into fixed sections:

• Positions 1–3: World Manufacturer Identifier — country, maker, vehicle type
• Positions 4–8: model, body, engine, and restraint attributes
• Position 9: a calculated check digit that validates the number
• Position 10: model year code — see the year chart
• Position 11: assembly plant
• Positions 12–17: unique production serial number

For a character-by-character walkthrough, see how to decode a VIN by hand, or just paste one into the free decoder.

Why there's no I, O, or Q

Those three letters are banned from every VIN to prevent confusion with the digits 1 and 0. This is also a built-in fraud test: any "VIN" containing I, O, or Q is invalid on its face.

What VINs are used for

Titles and registration, insurance policies, recall notices, theft recovery, service records, parts fitment, and — the reason most people look one up — vehicle history reports when buying used. Lenders also use the VIN to record liens, which is why a title check matters before handing over money.

A short history

Manufacturers began stamping identification numbers in the 1950s, but every maker used its own format. NHTSA standardized the 17-character system for the 1981 model year, which is why older vehicles need different handling — covered in our classic car VIN guide.

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Frequently asked questions

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