You are required to apply for a new passport if you have changed:

• Your name - by civil partnership, deed poll, marriage, or adds middle names, or goes back to your maiden name.
• Gender - even if you keep the same name.
• How you spell your name, e.g. changing from Jane to Jayne.

You don't need a new passport if you:

• Change your title, job, contact details or address.
• change your appearance, e.g. you dye your hair
• emigrate
• change your marital status but keep your name
• get nationality of another country whilst also holding British nationality