Changing your name is often one of the first and most meaningful steps in a male to female transition. It is a legal process that you can complete entirely on your own — you do not need a Gender Recognition Certificate, a court order, or a solicitor. A deed poll is a straightforward legal declaration that you have abandoned your former name and intend to be known by your new name in all situations from that point forward.
Once you have your deed poll, you can use it to update your records with the organisations that matter most to you: the Passport Office, DVLA, your bank, your GP, the NHS, HMRC, your employer, and any other body that holds records under your old name. Each organisation has its own process, but a correctly formatted deed poll is the document they will all ask for.
You do not need to change your gender marker at the same time as your name. Many trans women choose to update their name first, and address gender markers separately later if and when they wish to. There is no requirement to do both at once, and changing your name does not affect any future application for a Gender Recognition Certificate. This service generates a correctly worded, print-ready deed poll in seconds.