You haul for hire, you need a CDL and even a DOT number. Weight goes out the window when you go "commercial". Unless you are under 26,001 lbs AND take the "horse exemption" which allows you to haul and win prize money PROVIDED you DO NOT file a Schedule C on your income tax return. Prize money included in ordinary income. Pickup truck, farm trailer, Pinto race car with sponsor name/stickers and file Schedule C = CDL + possibly US-DOT number.
§ 390.3: General applicability.
(f) Exceptions. Unless otherwise specifically provided, the rules in this subchapter do not apply to—
(3) The occasional transportation of personal property by individuals not for compensation nor in the furtherance of a commercial enterprise;
If DOT/DPS stops him and he says "Guy paid me to carry this" or they ask for papers and can't show ownership, done right there. Also, he's crossing a state line (inferred) as a hired carrier and that is Interstate Commerce.
Our cars are owned by us, sticker free and no name, "Kelly Racing" etc on the trailer, truck, nothing. Our GVWR weight with the new trailer will be close to 25,000. That's one F350 + 34' box.
"NOT FOR HIRE" on the side of your truck is also meaningless per US-DOT and Tx DPS for sure.
You are required to obtain a USDOT number if you have a vehicle that:
Is used to transport the types and quantities of hazardous materials requiring a safety permit in intrastate commerce (see 49 CFR 385.403).
Has a gross vehicle weight rating or gross combination weight rating, or gross vehicle weight or gross combination weight, of 4,536 kg (10,001 pounds) or more, whichever is greater; or
Is designed or used to transport more than 8 passengers (including the driver) for compensation; or
Is designed or used to transport more than 15 passengers, including the driver, and is not used to transport passengers for compensation;
AND is involved in Interstate commerce:
Trade, traffic, or transportation in the United States—
Between a place in a State and a place outside of such State (including a place outside of the United States);
Between two places in a State through another State or a place outside of the United States; or
Between two places in a State as part of trade, traffic, or transportation originating or terminating outside the State or the United States.