North Carolina only if you sell bees is it required, but any apiary can be. The advantage of having it registered is that by state law you can keep people from spraying insecticides from a plane (crop dusting)with within a couple miles of the apiary. You are also required, if registered, to allow inspectors on your property at any time. Now this is out of a attorney's mouth, so take it for what its worth. We had a lawyer speak at our bee meeting a couple of months ago. He was actually really very informative and I appreciate him doing it.