While every bank or building society has their own method of updating your name, they usually follow a similar pattern. Banks tend to be fairly strict on the updating of names for security purposes, so it’s a good idea to have at least one form of ID in your new name before you begin. Most banks will require you to visit them in person via a branch, however, some will allow you to download a form, which you can return to them in the post. Before you go into the branch, make sure to check which documents you need. Once you have changed your name and/or gender, you will likely be issued with a new debit or credit card, and your bank statements will appear with your new name.
For bills or utilities, you will be able to do this over the phone or through their website. Using your search engine, search '(Your utilities provider) change name'. You will either need to fill in a form specific to them, or speak to someone over the phone.