A VIN (Vehicle Identification Number) is a vehicle’s unique identifier. It is typically 17 characters long and does not include the letters I, O, or Q to avoid confusion with 1 and 0. Before buying a used vehicle, it’s essential to check that the VIN on the registration certificate matches the markings on the vehicle itself.

Where the VIN is on the registration certificate

  • Look for a field labeled “Chassis number (VIN)” or “Vehicle identification number (VIN).”
  • It’s usually in the section with the vehicle’s technical details (near make, type, color, year of manufacture, etc.).
  • Compare every character: each number and letter must match exactly what you see on the vehicle.
  • If the printout is hard to read, ask to see a clear, original document; avoid relying on low‑quality copies.

Additionally, the same VIN is often listed in other documents the seller may have (service history, service invoices, insurance policy). All documents should agree with each other.

Where to find the VIN on the vehicle

Common places to find the VIN on a vehicle:

  • On a plate visible through the lower edge of the windshield on the driver’s side.
  • On a label or plate on the door frame (usually the B‑pillar) or on the driver/passenger sill.
  • Under the hood: on the firewall, fender apron, or strut tower.
  • Less commonly: on the floor under the carpet, in the trunk, or stamped on the chassis itself (often on off‑road and commercial vehicles).

Note: Vehicles can have multiple identifiers (a stamped VIN and/or factory plates and stickers). If a location is hard to access, ask the owner to safely move trim pieces or provide better access.

How to safely compare markings before you buy

  1. Preparation
  • Inspect in daylight or good lighting. Bring a cloth, a flashlight, and, if needed, a small mirror for hard‑to‑reach spots.
  • Clean dust and dirt around the marking to avoid scratching and misreading.
  1. Format check
  • Count the characters: there should be 17. If any are missing or there are extras, pause and investigate further.
  • Watch for the letters I, O, and Q — they are not used in a standard VIN.
  1. Compare with documents
  • Match the VIN from the registration certificate with the visible windshield VIN and the stamped (embossed) VIN on the body.
  • Photograph the VIN on the document and on the vehicle, then compare character by character. Use your phone’s zoom to avoid overlooking differences.
  1. Signs of possible tampering
  • Uneven depth or spacing of letters and numbers, mismatched fonts, or slanted characters.
  • Fresh paint/clearcoat, grinding marks, or a rippled/serrated surface around a stamped VIN.
  • Damaged, scratched, or unusually new rivets/fasteners on a plate; traces of removed or repositioned stickers.
  1. Consistency across all traces
  • The VIN on the registration certificate, on the vehicle, and in accompanying documents must be identical.
  • Treat any discrepancy — even a single character — seriously and investigate before deciding.
  1. Safety and access
  • Do not remove vehicle parts without the owner’s permission, and take care not to damage the markings.
  • If access is difficult, ask a professional for help or visit a workshop experienced in locating factory identifiers.

Conclusion: Compare the VIN in the registration certificate with at least two independent markings on the vehicle (the visible plate and a stamped VIN). Work slowly, in good light, and document with photos. This reduces risk and helps you make a safer purchase decision. For more tips and steps when buying a used car: Browse all guides.