Buick VIN Check
Every Buick vehicle manufactured for the North American market since 1981 carries a standardized 17-character Vehicle Identification Number (VIN) regulated by NHTSA under FMVSS 565 and ISO 3779. This code is unique to each vehicle and encodes the country of assembly, manufacturer identity, model attributes, engine configuration, model year, assembly plant, and production sequence number. Decoding a Buick VIN helps you verify a used-vehicle listing, confirm the correct parts and service history, check for open recalls, and detect potential title fraud.
Buick uses manufacturer-specific encoding in the Vehicle Descriptor Section (positions 4–8). Position 4 typically identifies the model line — for example, popular Buick models include Encore GX, Envision, Enclave. Position 8 usually encodes the engine type. Position 9 is a mathematical check digit that detects typos and many forms of VIN tampering. Position 10 encodes the model year, and position 11 identifies the assembly plant. All modern Buick VINs sold in North America begin with 1G4, indicating U.S. assembly under GM.
Buick is one of the oldest American automotive brands, founded in 1904. Today Buick focuses on premium crossovers and remains especially strong in the Chinese market.
How to Read a Buick VIN
To read a Buick VIN manually, start with the WMI (positions 1–3) to confirm the manufacturer and country of origin. For Buick, the WMI prefixes in our database include 1G4 and others depending on where the vehicle was built.
Position 4 encodes the Vehicle Line. Common values include A=Passenger car, B=Passenger car, C=Truck, D=Multi-purpose, E=Incomplete vehicle, F=SUV. Position 5 encodes trim or series level. Position 8 encodes the engine (A=2.0L Turbo 4-cyl, B=2.5L 4-cyl, C=3.6L V6, D=5.3L V8, E=6.2L V8). Position 9 is the check digit — our decoder validates it automatically using the ISO 3779 weighted-sum algorithm. Position 10 is the model year (see our year-code reference), and position 11 is the assembly plant (A=Lansing, MI, B=Bowling Green, KY, C=Detroit, MI, D=Lordstown, OH, E=Fort Wayne, IN). Positions 12–17 are the unique serial number for that vehicle.
Because Buick may change VDS encoding between model years, treat decoded attributes as informational. Always confirm critical details (engine, trim, drivetrain) against the window sticker, build sheet, or dealer records.
Buick VIN Position Breakdown
| Pos. | Section | Standard Meaning | Buick Notes |
|---|---|---|---|
| 1 | WMI | Country of manufacture | ISO 3779 region code — e.g. 1=USA, J=Japan, W=Germany |
| 2 | WMI | Manufacturer | Combined with pos. 1–3 identifies Buick |
| 3 | WMI | Vehicle type | Buick WMI codes: 1G4 (United States) |
| 4 | VDS | Vehicle Line | A=Passenger car; B=Passenger car; C=Truck; D=Multi-purpose; E=Incomplete vehicle; F=SUV; G=Van; H=Commercial truck |
| 5 | VDS | Series | Trim, series, or drive configuration |
| 6 | VDS | Body / restraint | Body style and/or restraint system (varies by year) |
| 7 | VDS | Restraint / body | Supplemental restraint or body attribute |
| 8 | VDS | Engine | A=2.0L Turbo 4-cyl; B=2.5L 4-cyl; C=3.6L V6; D=5.3L V8; E=6.2L V8; F=6.6L Duramax Diesel |
| 9 | Check digit | Validation | ISO 3779 weighted-sum check — detects typos and tampering |
| 10 | VIS | Model year | Standard 30-year letter/digit cycle (1980–2039) |
| 11 | VIS | Assembly plant | A=Lansing, MI; B=Bowling Green, KY; C=Detroit, MI; D=Lordstown, OH; E=Fort Wayne, IN; F=Flint, MI |
| 12–17 | VIS | Serial number | Unique production sequence at the assembly plant |
Frequently Asked Questions — Buick VIN
Where is the VIN on a Buick?
Driver's side dashboard and door jamb certification label.
What does 1G4 mean in a Buick VIN?
The WMI prefix 1G4 identifies a Buick vehicle. All modern Buick VINs sold in North America begin with 1G4, indicating U.S. assembly under GM.
How do I decode a Buick VIN for free?
Enter your 17-character Buick VIN in the decoder above. Our engine validates the check digit, reads the model year, identifies the assembly plant, and applies Buick-specific rules for positions 4–8 where available.
Can a Buick VIN tell me the engine type?
For most Buick models, position 8 encodes the engine family or displacement. Our decoder maps this using manufacturer data. Popular models like Encore GX and Envision are supported.
What plants build Buick vehicles?
Position 11 is the assembly plant code. Buick operates factories worldwide — our decoder translates the plant letter to a city and country. All modern Buick VINs sold in North America begin with 1G4, indicating U.S. assembly under GM.
How do I verify a Buick VIN is genuine?
Use our decoder to validate the check digit at position 9. A valid Buick VIN like 1G4AL5SM20F012345 must pass the ISO 3779 check-digit test. Also compare the dashboard VIN with the door jamb label — mismatches may indicate tampering.
Does the model year in a Buick VIN match the calendar year?
Not always. Position 10 encodes the model year using the standard 30-year ISO cycle. A vehicle assembled in late 2024 may carry a 2025 model-year code. Always treat position 10 as the manufacturer's designated model year.
Which Buick models can I decode?
Our decoder supports all Buick models with standard 17-character VINs since 1981, including Encore GX, Envision, Enclave. WMI lookup works for every Buick VIN; detailed trim and engine data is available where manufacturer encoding is documented.