VIN vs chassis number

Client

VIN vs chassis number: colloquial chassis number often means the same 17-character VIN on modern road vehicles, but older or import frames may use shorter stamps. This tool expects the standardized 17-character layout.

When labels differ

Heavy equipment or pre-standardization imports may use other serial schemes. Paste what you have—length and charset guards show whether ISO 3779 rules apply.

Privacy: parsing runs only in your browser. This page does not query DMV, insurance, or manufacturer databases—only the published mod-11 rule for the ninth character.
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After removing spaces and hyphens, the frame must be exactly 17 characters. Letters I, O, and Q are forbidden everywhere. Position 9 (index 8) is the check symbol: decimal 0–9 or X for remainder ten. Each symbol maps to a numeric value, is multiplied by a fixed weight for its position, products are summed, and sum mod 11 must equal the check symbol’s value (X → 10).

Result

Passes check digit — weighted sum mod 11 is 10; expected X.

  • WMI (positions 1–3): 1HG
  • Attributes (4–8): BH41J
  • Check (9): X
  • Model year code (10): M
  • Plant (11): N
  • Sequential (12–17): 109186

Common use cases

  • Explain why pre-1981 frames fail length guards.
  • Map informal paperwork labels to the VIN field.

Common mistakes to avoid

  • Expecting a separate chassis checksum algorithm

    On modern US-label vehicles the public check digit is part of the VIN itself.

FAQ

Is chassis number the same as VIN?

Often yes on modern vehicles—the VIN is the standardized identification number.

Common search terms

Phrases people search for that match this tool. See the full long-tail keyword index.

  • vin check digit verifier online
  • validate vin number mod 11 free
  • ninth position vin checksum browser
  • iso 3779 vin check digit calculator
  • vehicle identification number check digit locally

More tools

Related utilities you can open in another tab—mostly client-side.