This Practice Note considers the law relating to the operation of small civilian drones (also referred to as unmanned aerial vehicles or UAVs, unmanned aircraft, small unmanned aircraft or SUAs) for commercial and recreational purposes. It looks at the International, European and domestic regulatory framework with particular emphasis on the Air Navigation Order, the Retained Implementing and Delegated Regulations and the open, specific, and certified categories. It also considers issues of criminal and civil liability that may arise when using a drone including trespass, negligence and nuisance.