If the gross vehicle weight of the truck plus the gross vehicle weight of the trailer exceeds 26,001 pounds you need a CDL. It does not matter whether you’re hauling commercially or not. If the DOT pulls you over and checks the gross vehicle ratings on both the truck and the trailer they can write you for not having the CDL.
I have had the DOT pull me over because he ran my tag on the trailer, and when it did not come up as a CDL, his lights went on. The officer was infuriated when he realized he could not give me a ticket for not having a CDL. my truck gross weight is 11,400 pounds. My trader gross weight is derated to 14,500 pounds. This combination puts me at 25,900 pounds. The man then spent 45 minutes trying to find something to write me up on. I made the mistake of using the safety chain hook to also hook the breakaway cable. He told me that it needed to be on a separate attachment point. So I reached in my pocket pulled out a carabiner and hooked the safety cable to the ring in the bed of the truck. I asked him if that was correct and he said yes.
He then went to his car and wrote me an out of service ticket. He stated that I was out of service because of the breakaway cable. When he gave me the out of service ticket I ask him if he did not see me correct the problem. He simply said have a good day turned around and walked away.
By law, I’m not supposed to move the truck until the out of service ticket is corrected. Since I had corrected it with him present, I went on my way.
I then found at the bottom of the ticket and extremely small print were the instructions that I had to sign the ticket that the problem was corrected and fax the ticket into the DOT. Failure to do this would have resulted in a fine of several thousand dollars per day if I was caught running the truck without the correction notice being sent in.
That same DOT cop has now pulled me over four times.