How to Validate a 17-Character VIN
A VIN is valid when it has 17 characters, uses only allowed letters and digits, and, in many markets, has a matching check digit.
1. Count 17 characters
Modern VINs, standardized since 1981, have exactly 17 characters. Remove spaces and dashes before counting. A missing or extra character is the most common reason a VIN is rejected.
2. Check for I, O and Q
VINs use the digits 0–9 and the letters A–Z except I, O and Q, which are easily confused with 1 and 0. Korea Car VIN accepts lowercase input and converts it to uppercase for you.
3. Know what each position means
| Position | Name | What it tells you |
|---|---|---|
| 1–3 | World manufacturer identifier (WMI) | Who built the vehicle. Korean-built vehicles start with K. |
| 4–8 | Vehicle descriptor section (VDS) | Model line, body and engine. Each manufacturer defines these. |
| 9 | Check digit | A digit or X calculated from the other 16 characters. |
| 10 | Model year | Same code table for every brand. |
| 11 | Plant | Where the vehicle was assembled. |
| 12–17 | Serial number | The vehicle's production sequence. |
4. Verify the check digit
Convert each letter to a number, multiply every position by its weight, add the results and divide by 11. The remainder is the check digit; a remainder of 10 is written as X. Here is the calculation for the example VIN 1M8GDM9AXKP042788:
| Position | Character | Value | Weight | Product |
|---|---|---|---|---|
| 1 | 1 | 1 | 8 | 8 |
| 2 | M | 4 | 7 | 28 |
| 3 | 8 | 8 | 6 | 48 |
| 4 | G | 7 | 5 | 35 |
| 5 | D | 4 | 4 | 16 |
| 6 | M | 4 | 3 | 12 |
| 7 | 9 | 9 | 2 | 18 |
| 8 | A | 1 | 10 | 10 |
| 9 | X | 7 | 0 | 0 |
| 10 | K | 2 | 9 | 18 |
| 11 | P | 7 | 8 | 56 |
| 12 | 0 | 0 | 7 | 0 |
| 13 | 4 | 4 | 6 | 24 |
| 14 | 2 | 2 | 5 | 10 |
| 15 | 7 | 7 | 4 | 28 |
| 16 | 8 | 8 | 3 | 24 |
| 17 | 8 | 8 | 2 | 16 |
North American VINs must have a correct check digit. VINs of vehicles made for the Korean market often do not follow this rule, so a mismatch there is common and does not make the VIN invalid. Korea Car VIN still decodes those VINs and shows a notice.
FAQ
Can a VIN have fewer than 17 characters?
Vehicles built since 1981 use 17-character VINs. Older vehicles may have shorter numbers, which cannot be decoded with the 17-character format.
Does a correct check digit prove the VIN is real?
No. The check digit only catches most typing mistakes. It does not confirm that a vehicle with that VIN exists or that the VIN belongs to the car in front of you.
Why can't I type I, O or Q in a VIN?
These letters are left out of the VIN standard because they are easily confused with 1 and 0. If you see one on a document, it is almost always a 1 or a 0.
Korea Car VIN is an independent service and is not affiliated with any vehicle manufacturer. Position meanings on this page come from our own sales records, not from manufacturer documentation, and may not apply to every vehicle.