Apologies for repeating this again but it appears at least some are not aware.
In the UK, you can call yourself almost whatever you like. The exception is, you cannot use a name which appears to give you a title to which which you have no right. Thus I could not call myself King John or Sir John, but I could all myself Mary, or Anne or Fred or Saturday etc.
In the UK there is no law, which dictates which name you must use. Thus on marriage it is only custom that women usually take the surname of their husbands. There is no requirement to do so.
There are three ways in which one can change their name (1) by common law. One just says, as of now I am ……. New name. (2) Do the same but on oath before a Magistrate (3) Make Deed Poll.
No way is no more legal than the other. Over 25 years ago I did it by Common Law.
When changing a name, one can change all documentation into the new name, except one’s birth certificate.
So to all you women getting married, do what YOU want.