OK...here goes again.
This is for California drivers.
After reading the new California Drivers Handbook, I was more confused than ever, so.
I went to my local CHP (California Highway Patrol) and spoke with the officer that monitors local commercial vehicles.
As long as I drive the truck without any load on/in the bed I will be fine, but as soon as I put anything on the bed...even a grocery bag. It becomes a commercial vehicle and requires a CDL and a "CA number" and if I load dirt or other commodity I need a CPUC number also. This is regardless of weight issues or 26,001 lbs.
Also, I had to get a "smog exemption" for it from the local Air Quality Control Board and Air Resources Board.
The California CDL was not to hard to get, except I had to drive 70 miles to take the drivers driving test and a physical. The "CA number" was free from CHP office.
As long as I do not load the flat-dump bed with lumber or dirt I do not need a CPUC number/permit. Oh yeah and not for hirer.
To be sure check with your local DMV and/or State Trooper/Highway Patrol.
Talk with the guy who writes the tickets...;}
Further....my vehicle insurance company required that I get a CDL. So you might want to check with your insurance carrier too.