A commercial Class A license, also referred to as a Class A CDL, is required to operate various commercial vehicles with a gross combination weight rating of 26,001 pounds or more. This is also necessary if you will be towing a trailer that is in excess of 10,000 pounds, although what your towing allowance is depends on any endorsements you obtain. While there are several different considerations involved, typically with a commercial Class A license, you will be able to drive a tractor-trailer, a truck and trailer combination, a tractor-trailer bus, tanker vehicle, livestock carrier, or flatbed truck. You might also qualify to drive some Class B and Class C vehicles with the correct endorsement in place.