Do you need a license to pull a utility trailer?

If the total weight rating of the combination is over 26,000 lbs., then yes, you will. If the trailer itself is rated at over 10,000 lbs., you will need a Class A CDL. If it is rated at under 10,000 lbs., then you would need a Class B CDL. Note that this only applies to combinations over 26,000 lbs. GVWR - you can pull a 15,000 lb. rated trailer behind a 10,000 lb. rated truck with a regular Class C licence, but, if you pulled that same trailer behind a 15,000 (or more) rated truck, you'd be operating a combination rated over CDL weight, and would require a Class A CDL.