VIN forbidden letters

Client

Standardized VINs forbid letters I, O, and Q everywhere to avoid confusion with digits 1 and 0. Paste a frame to see charset errors before checksum calculation.

Charset before checksum

Validation fails fast on forbidden letters. Allowed letters use the ISO transliteration table (A–Z except I, O, Q) plus digits 0–9.

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.
?

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

  • Catch OCR substitutions from handwritten notes.
  • Explain rejection reasons in data-entry training.

Common mistakes to avoid

  • Replacing O with 0 without re-reading the sticker

    The physical label never contained O—likely a different letter or digit.

FAQ

Why are I O Q not allowed in VINs?

They are easily confused with 1 and 0 on stamped plates and OCR.

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

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