Understanding VINs

A Vehicle Identification Number (VIN) is a unique 17-character code that identifies a specific vehicle. Based on ISO standards 3779 and 3780, VINs are crucial for accurate vehicle identification and tracking.

VIN Standards

VINs follow standards established by the International Organization for Standardization (ISO):

ISO 3779: Defines the VIN structure
ISO 3780: Establishes the World Manufacturer Identifier system

Different regions have compatible but distinct implementations:

Name
North America (>2,000 vehicles/year)
Description
WMI + Vehicle attributes + Check digit + Model year + Plant code + Sequential number
Name
North America (≤2,000 vehicles/year)
Description
WMI + 9 + Vehicle attributes + Check digit + Model year + Plant code + Manufacturer ID + Sequential number
Name
European Union (>500 vehicles/year)
Description
WMI + Vehicle characteristics + Vehicle identification
Name
European Union (≤500 vehicles/year)
Description
WMI + 9 + Vehicle characteristics + Manufacturer ID + Vehicle identification

VIN Structure Overview

Name
WMI (1-3)
Type
string
Description
World Manufacturer Identifier - region and manufacturer codes.
Name
VDS (4-8)
Type
string
Description
Vehicle Descriptor Section - vehicle attributes and platform.
Name
Check Digit (9)
Type
string
Description
Validation digit (required in North America and China).
Name
VIS (10-17)
Type
string
Description
Vehicle Identifier Section - unique vehicle details.

Example VIN Breakdown

1HD1KB4157Y123456
│││││││││││└──────┘
│││││││││││ Serial number (12-17)
│││││││││││
││││││││││└─ Plant code (11)
│││││││││└── Model year (10)
│││││││└──── Check digit (9)
││││││└───── Engine type (8)
│││││└────── Body type (7)
││││└─────── Series (6)
│││└──────── Restraint system (5)
││└───────── Platform (4)
│└────────── Make (2-3)
└─────────── Region (1)

World Manufacturer Identifier (WMI)

The first three characters identify the manufacturer and region. For manufacturers producing fewer than 1,000 vehicles per year, the third digit is '9', with additional identification in positions 12-14.

Region Codes (First Character)

Name
A-C
Description
Africa
Name
J-R
Description
Asia
Name
S-Z
Description
Europe
Name
1-5, 7
Description
North America
Name
6
Description
Oceania
Name
8-9
Description
South America

Common examples:

1, 4, 5, 7: United States
2: Canada
3A-3W: Mexico
J: Japan
K: Korea
L: China
W: Germany
VF-VR: France
SA-SM: United Kingdom

Vehicle Descriptor Section (VDS)

Characters 4-9 describe the vehicle's attributes and include a check digit. The VDS format varies by manufacturer but typically includes:

Name
Platform (4)
Type
string
Description
Vehicle line, platform, or model series.
Name
Restraint (5)
Type
string
Description
Safety and restraint system type.
Name
Body (6-7)
Type
string
Description
Body style and series information.
Name
Engine (8)
Type
string
Description
Engine type and size.
Name
Check Digit (9)
Type
string
Description
Calculated validation digit.

Vehicle Identifier Section (VIS)

The final eight characters (10-17) uniquely identify the specific vehicle:

Name
Model Year (10)
Type
string
Description
Single character encoding the vehicle's model year.
Name
Plant Code (11)
Type
string
Description
Manufacturing plant identifier.
Name
Sequential Number (12-17)
Type
string
Description
Production sequence number, with positions 12-14 used for additional manufacturer identification in some cases.

Model Year Encoding

The 10th position encodes the model year using a specific pattern:

Name
A-Y
Description
1980-2000 (excluding I, O, Q)
Name
1-9
Description
2001-2009
Name
A-Y
Description
2010-2030 (excluding I, O, Q)
Name
1-9
Description
2031-2039

Year Codes

Code Year  Code Year  Code Year
A    2010  L    2020  Y    2030
B    2011  M    2021  1    2031
C    2012  N    2022  2    2032
D    2013  P    2023  3    2033
E    2014  R    2024  4    2034
F    2015  S    2025  5    2035
G    2016  T    2026  6    2036
H    2017  V    2027  7    2037
J    2018  W    2028  8    2038
K    2019  X    2029  9    2039

Check Digit Calculation

The 9th position contains a check digit that validates the VIN's authenticity. Here's how it's calculated:

Transliterate Letters: Convert letters to numbers using this system:

A=1 B=2 C=3 D=4 E=5 F=6 G=7 H=8 J=1
K=2 L=3 M=4 N=5 P=7 R=9 S=2 T=3 U=4
V=5 W=6 X=7 Y=8 Z=9

Apply Weights: Multiply each digit by its weight factor:

Position: 1  2  3  4  5  6  7  8  9  10 11 12 13 14 15 16 17
Weight:   8  7  6  5  4  3  2  10 0  9  8  7  6  5  4  3  2

Calculate: Sum products and divide by 11. The remainder is the check digit (X if 10).

The letters I, O, and Q are never used in VINs to avoid confusion with numbers.

Using VINs with the API

Example: VIN Decoding

// Decode a VIN using our API
const response = await fetch(
  'https://api.cardog.io/v1/vin/corgi/1HD1KB4157Y123456',
  {
    headers: {
      'x-api-key': 'your-api-key'
    }
  }
)

const result = await response.json()
console.log('Vehicle:', result.components.vehicle)

Response

{
  "vin": "1HD1KB4157Y123456",
  "valid": true,
  "components": {
    "vehicle": {
      "make": "Harley-Davidson",
      "model": "Sportster",
      "year": 2007,
      "bodyStyle": "Motorcycle"
    },
    "wmi": {
      "manufacturer": "Harley-Davidson Motor Company",
      "make": "Harley-Davidson",
      "country": "United States",
      "region": "North America"
    },
    "checkDigit": {
      "isValid": true,
      "expected": "5",
      "actual": "5"
    }
  }
}

VIN Physical Locations

VINs are typically found in several locations on a vehicle:

Lower corner of the windshield (driver's side)
Under the hood near the latch
Front end of the vehicle frame
Driver's side door pillar

The Cardog API can help identify the exact VIN locations for specific makes and models.

Next Steps

Try VIN decoding with our API endpoints
Learn about market analysis using VINs
Explore vehicle research capabilities
Check out our API documentation for all available endpoints