How to Read a VIN Number

Every vehicle sold in the United States since 1981 carries a 17-character Vehicle Identification Number. Once you know what each position means, a VIN tells you the vehicle's origin, manufacturer, body type, engine, model year, assembly plant, and production sequence — all without a lookup. This guide walks through every position so you can decode any modern VIN by hand and understand what a VIN decoder like VinMole is actually reading.

The Three Sections of a VIN

NHTSA divides the 17 characters into three logical sections: the World Manufacturer Identifier (positions 1–3), the Vehicle Descriptor Section (positions 4–9), and the Vehicle Identifier Section (positions 10–17).

Positions 1–3: World Manufacturer Identifier (WMI)

The first three characters identify who built the vehicle and where. Position 1 is the country of manufacture: for example, 1, 4, and 5 indicate the United States; J indicates Japan; W indicates Germany; K indicates South Korea. Position 2 narrows down the manufacturer within that country, and position 3 specifies the vehicle type or manufacturing division.

Together these three characters form the WMI, which is assigned and maintained by NHTSA for North American manufacturers and by ISO internationally. Manufacturers producing fewer than 500 vehicles per year receive a 9 in position 3 and use positions 12–14 to extend the identifier.

Positions 4–8: Vehicle Descriptor Section (VDS)

These five characters describe the vehicle itself. Their exact meaning is defined by each manufacturer — NHTSA does not standardize what each position represents within the VDS. Common uses include body style, restraint systems, engine type, and model line. To interpret these characters accurately, you need the manufacturer's own VIN guide or a decoder that has their mapping data.

Running a VIN through the NHTSA vPIC decoder or VinMole will translate these positions into plain-English attributes for most modern vehicles.

Position 9: Check Digit

The ninth character is a mathematically derived check digit. NHTSA defines a weighted algorithm: each of the other 16 characters is assigned a numeric value and a positional weight, the products are summed, and the remainder after dividing by 11 produces the check digit (0–9, or X for 10). Any VIN that fails this calculation is either mistyped or fraudulent. Most VIN decoders validate this automatically.

Position 10: Model Year Code

Position 10 encodes the model year as a single character. Six characters are excluded from the year-code alphabet to avoid confusion: the letters I, O, Q, U, and Z (which resemble digits or create ambiguity) and the digit 0. The sequence cycles every 30 years. Below is the complete table for the current cycle:

Note that the cycle repeats: code A was used for 1980 and 2010, and will be used again for 2040. For modern vehicles the year is unambiguous, but for classics you may need additional context.

Position 11: Plant Code

Position 11 identifies the specific assembly plant where the vehicle was manufactured. Each manufacturer assigns their own plant codes, so the same letter can mean different factories at different automakers. NHTSA maintains a registry, and VIN decoders can translate this character when the manufacturer data is available.

Positions 12–17: Production Serial Number

The final six characters are the vehicle's sequential production number within its plant for that model year. This sequence, combined with the WMI (positions 1–3), uniquely identifies every vehicle a manufacturer produces. For manufacturers with a small production volume, positions 12–14 may extend the WMI as noted above.

Pre-1981 VINs

Before the 1981 standardization, automakers used their own VIN formats. These sequences vary significantly in length and structure — some are as short as 11 characters, and the position meanings differ entirely from the modern standard. Decoding a pre-1981 VIN requires manufacturer-specific guides. The tools on this site and NHTSA's vPIC are designed for standardized 17-character VINs.

Decode Your VIN

Now that you know what each position means, you can use VinMole to get a full structured breakdown — manufacturer details, body type, engine, model year, recall campaigns, consumer complaints, NCAP crash ratings, and EPA fuel economy — all from public NHTSA data. Enter your 17-character VIN on the home page. No account needed.

For the official government decoder, NHTSA also provides a free tool at vpic.nhtsa.dot.gov.

Frequently Asked Questions

How many characters are in a VIN?

Since 1981, all vehicles sold in the United States are required to have a standardized 17-character VIN. Vehicles manufactured before 1981 used shorter, non-standardized sequences that vary by manufacturer.

What does the 10th character of a VIN mean?

Position 10 is the model year code. Each letter or digit maps to a specific model year. For example, A = 2010, B = 2011, and so on through Y = 2030. The letters I, O, Q, U, Z and the digit 0 are excluded from year codes to avoid confusion with similar-looking characters.

What is the check digit in a VIN?

Position 9 is the check digit — a single character (0–9 or X) calculated from the other 16 characters using a weighted formula defined by NHTSA. It is used to detect typos and fraudulent VINs. A VIN that fails the check digit calculation is invalid.

How do I find the VIN on my car?

The most common location is the driver-side dashboard, visible through the windshield at the base. It also appears on the driver-side door jamb sticker, on the engine block, and on your vehicle title and registration documents.

Can I decode a VIN for free?

Yes. NHTSA's free vPIC API (vpic.nhtsa.dot.gov) is the official government decoder. VinMole also uses this data — enter your VIN on the home page to get a full structured report including recalls, complaints, and fuel economy.