That looks very much like a hornet. Kill it and it sends a distress signal via pheromone and you’ll have three more there in no time. Their sting hurts like hell. At least that’s my experience. Never seen one in the U.K., but plenty where I holiday.
We have them occasionally banging against the windows of an evening if the lights are on inside. I see them buzzing about outside too sometimes but they never bother us. I assume there must be a nest nearby.
