What driver licence is required to drive box truck under 26000 lb with air brakes?

Situation dependent. If it is a New York registered commercial vehicle, New York has a unique law requiring all commercial vehicles 18,001 lbs. Gross Vehicle Weight Rating and up (vs. 26,001 lbs. GVWR in the remaining states) to be driven by an operator with a Commercial Drivers License (CDL). A Class C CDL would be required in this instance. Additionally, applicable to all states, if the vehicle is transporting a quantity of hazardous materials which requires placards to be displayed IAW CFR 49, a Class C CDL (minimum) with hazmat endorsement is required. Additionally, and also applicable to all states, if the vehicle is a bus designed to transport more than 15 persons (including the driver), then a Class C (minimum) CDL with passenger endorsement is required (a specific school bus endorsement is required if the vehicle is a school bus). In all three instances listed above, you would need to take the General Knowledge written CDL test, the written air brakes test, and you would have to road test in an air brake equipped vehicle of the appropriate class. If you do not complete and pass both the written air brake tests and perform your road test in an air brake equipped vehicle, you get a restriction prohibiting you from operating a CMV (vehicle requiring a CDL) which is equipped with air brakes - there is no air brake endorsement. Additionally, you would have to take the hazardous materials or passenger written tests, if applicable to your situation. The hazardous materials endorsement also requires fingerprinting and a background check by the TSA (it costs around $94). For the passenger endorsement, a road test must be conducted in a passenger bus of the appropriate class. The school bus endorsement also incurs a background check.

Although your truck may not require a CDL, you will be required to obtain a DOT medical card if it is used for commercial purposes.

For private, non-commercial use, your state's standard drivers license is all you need. E.g., you rent a U-Haul truck to move your furniture. Unfortunately, while CDL drivers are strictly regulated and scrutinized, the same doesn't hold true for everyday non-CDL drivers.

addition;

I drove trucks cross country with my own truck's and trailer's for 12 years than drove locally hauling overweight sheet rock (100,000+) until 96. The short simple answer is you do not need a cdl for a vehicle under 26001 lbs, air brakes or not. If you haul Hazardous material, you need a class c with a hazmat endorsement and you must take your road test in a truck with air brakes and pass the general knowledge test for cdl. If you take the road test in a truck without air brakes, you will have an air brake restriction. So, as long as your not hauling hazmat and is not a bus hauling 16 or more persons and your truck is registered for less than 26,001 lbs you do not need a cdl.