VIN check digit

Client

The VIN check digit sits at position nine (index eight). When OCR misreads one symbol, the body may still be correct. This page shows pass/fail and the symbol that would make the string valid.

Mod-11 weight positions

ISO 3779 assigns weights 8,7,6,5,4,3,2,10,0,9,8,7,6,5,4,3,2 across positions 1–17. Position nine’s weight is zero in the sum—the check symbol is compared to the remainder, not multiplied.

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

  • Fix one wrong ninth character without re-scanning the windshield sticker.
  • Document expected check symbol in QA specs for label vendors.

Common mistakes to avoid

  • Changing the check digit without verifying WMI and sequential fields

    Mod-11 fix does not prove the middle digits belong to your manufacturer range.

FAQ

How is the VIN check digit calculated?

Each character maps to a value, multiplied by a fixed position weight, summed, remainder mod 11—printed as digit or X.

Why can the check symbol be X?

When the remainder is ten, printers use letter X at position nine.

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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