Don't worry about names.
In UK one can chose to change their name at any time, providing it is not for a dishonest reason nor appears to give one a title such as Sir, or Lord. So could nor be Lord John Smith. etc.
I changed my name 25 years ago by Common Law. I just said as from a certain date I am now J....... C ---------- I got a note from a police officer ( person who can countersign an application) to say he had known me for a number x years and that as of ..... I had changed my name. I went to Passport Office got my new passport in my new name, no reference to birth name, and over the few weeks changed my DL, Credit cards, medical card etc.
One can also make the change by statutory declaration (pay a solicitor to say you have done it) and then if one wishes they can register the change with a Deed Poll, but this is not a legal requirement I did not do it.
The same applies when a woman marries. She has no obligation to change her name, nor to adopt her husbands name. My wife kept her surname and added mine. As we live in Spain this was an asset as people have two surnames. She is now just like the Spanish. I still have just one surname.
