I'm working from memory only on this.
I believe Brits can TECHNICALLY own shotguns, however the use of one is ALWAYS viciously prosecuted and the homeowner is jailed for years, even for resistance inside the home to multiple knife bearing Home Invasion Perps, while the perps get diversion programs.
If perps are getting diversion programs after home invasion shotgun defensive measures, go up a few notches in shot size or hit head shots. The head of a human is big as a pheasant. My personal preference is 3 or 4 buckshot at 50 feet the target is penetrated bigly. Just saying.