Bangers have been illegal to sell or buy bangers in the UK since 1997. This is due to being labelled as potentially harmful and a nuisance firework. Along with Mini rockets, firecrackers, jumping jacks or fireworks with erratic flight and Airbombs.
Yes, you can. Under the law, you must have permission of the land owner to let off fireworks. So if it is your property you can set off your fireworks in your backyard. From sparklers, to fountains or rockets. Always make sure you buy fireworks safe for your garden.