Agricultural Truck Requirements

I am told in Georgia farm trucks do not have to have a name on the door or a DOT#. Now any truck above 10,001 Lbs rating needs a DOT # if crossing state lines even as a passenger vehicle. No problem.
Years ago when I worked for someone else he got temporary IFTA's if I went to Florida. Moving their own equipment. They jumped across the line to SC without one on a regular basis. Hauling grain, their own.
Now if I go to SC and bring products back, purchased for the farm, is this required?