How to Decode a VIN, Position by Position

Every 17-character VIN follows the same outline, set by ISO 3779 internationally and by 49 CFR Part 565 in the United States. What changes between markets is how much each part is required to contain.

When we ran the example through NHTSA's vPIC decoder on September 25, 2026, it returned “VIN decoded clean. Check Digit (9th position) is correct” and filled 68 of its 154 data fields. The main values are below. Changing a single character, for example the final 5 to a 4, makes vPIC report that the check digit “does not calculate properly”.

1. Position 1 – region and country. A–C are Africa, H–R Asia, E and S–Z Europe, 1–5 and 7 North America, 6 Oceania and 8–9 South America. The full allocation is in our WMI codes guide.
2. Positions 2–3 – manufacturer. The first three characters form the World Manufacturer Identifier. Most makers use the third character for a division or vehicle type: 1FA is Ford passenger cars, 1FT Ford trucks and 1FM Ford multipurpose vehicles.
3. Positions 4–8 – vehicle descriptor. The manufacturer decides which character stands for what, but must file the key with NHTSA. On cars, SUVs and trucks up to 10,000 lb gross vehicle weight rating, position 7 must be a letter for vehicles built since April 30, 2009.
4. Position 9 – check digit. A number from 0 to 9, or X for 10, that lets anyone detect most copying mistakes. See how the check digit works.
5. Position 10 – model year. One of 30 codes that repeat every 30 years; I, O, Q, U, Z and 0 are never used. Our model year chart lists 1980 to 2039.
6. Position 11 – plant. The factory where the manufacturer attached the VIN. Codes are manufacturer-specific, so a decoder needs the maker's key to name the plant.
7. Positions 12–17 – serial number. The production sequence. On cars and light trucks the last five characters must be digits; on other vehicles, the last four. Low-volume makers use 12–14 to finish their manufacturer code and 15–17 for the serial.

The outline is shared, but EU rules have historically required much less inside it. Implementing Regulation (EU) 2021/535 added a mandatory check digit, yet it still leaves the model year and plant to the manufacturer. That is why European-market VINs often decode only partially; our European VIN guide covers this in depth.

1. Copy the VIN from the vehicle itself, not from an advert. Remove spaces and dashes and confirm it is exactly 17 characters.
2. Check for illegal characters. An I, O or Q means the VIN was copied wrongly; the intended character is usually 1 or 0.
3. Look up the first three characters in the WMI table to identify the manufacturer.
4. Recalculate the check digit. On a North American vehicle from 1981 or later, a mismatch means at least one character is wrong.
5. Read the model year from position 10, using position 7 to choose between the two 30-year cycles.
6. Run the VIN through a decoder backed by manufacturer data, such as our VIN decoder, to translate positions 4–8 and 11.
7. Compare the result with the vehicle in front of you: body style, engine, model year and the VIN on the door-frame label should all agree.

Most free decoders, ours included, rely on NHTSA's vPIC database, and vPIC attaches a numbered status message to every decode. Knowing the common ones tells you whether to trust a result or re-check the VIN. These are the messages we saw while testing the examples in this guide on September 25, 2026.

A clean decode confirms the VIN is consistent with the manufacturer's data, not that the vehicle is what it claims to be. vPIC can hold more than 150 fields per VIN, but no vehicle fills them all: our example filled fewer than half, because manufacturers only encode some details. Treat blank fields as “not encoded”, not as “not fitted”.

• A typing error. This is the most common cause. The check digit usually catches it, and vPIC reports which positions look wrong.
• Wrong length. Anything other than 17 characters is either mistyped or from a vehicle built before the 1981 standard.
• Not built for the U.S. market. NHTSA says vPIC covers vehicles intended for sale or import into the United States and returns limited data for others.
• Unencoded details. Trim level, colour and options are often not in the VIN at all, so those fields stay blank.
• A code the manufacturer never filed. Some positions decode only partly, and vPIC lists them as unused or unknown.

If a decode looks wrong, first compare the VIN on the dashboard plate with the one on the door-frame label and your paperwork. Our guide on where to find your VIN lists every location to check.