If you want to declutter your wardrobe there are many charties out there to help you achieve your goal . If you have bags of clothes to get rid of and don't have a vechicle I would recommend Traid, Litta, Redonate or the Council. What's great about them is that they pick up your clothes from your door step.
I would also recommend donating to Cancer Research or Samaritans. There are many shops on the UK high street. You will have take the clothes to your local shop.