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SESK: Stuff Everyone Should Know · sesk.info/cdl-endorsement-x-tank-hazmat

What does the X endorsement on a CDL stand for?

Tank vehicle plus hazardous materials combined.

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  1. Tank vehicle and hazmat combined ✔
  2. Extra-long trailers
  3. Oversize loads

Why: X is a single code that means the driver holds both the tank vehicle (N) and hazardous materials (H) endorsements. Fuel tanker drivers usually carry it.

Huh, didn't know that: States may add their own extra codes, but they must explain them on the license.

The dad joke
Why did the fuel tanker get good grades? It always passed with flying colors.
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References

Answer: Tank vehicle and hazmat combined. X is a single code that means the driver holds both the tank vehicle (N) and hazardous materials (H) endorsements. Fuel tanker drivers usually carry it.

  1. 49 CFR 383.153 Information on the CLP and CDL documents (eCFR) www.ecfr.gov/current/title-49/section-383.153
    X for a combination of tank vehicle and hazardous materials endorsements
    Checked 2026-10-10.

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