Independent celebrant-led weddings are not currently legal in the UK. To legally register your marriage you will need to have As the law currently stands, you will need to have a separate civil service, this is the 'admin' part of the process, and does not need to be treated as a formal ceremony.
Lots of couples chose to do ‘the legal bit’ at their local Registry Office a couple of days before their big day (this costs around £50 for a basic service). I chose to do this and I am happy to discuss this further if you have any questions. But the process is pretty simple and it’s basically just completing the legal paperwork. The whole thing is just a short appointment that involves signing the marriage licence and saying a few contracting words in front of 2 witnesses of your choice, you don’t have to share vows or exchange rings. All the good stuff can be saved for your soulful celebrant led ceremony.