You may wish to apply for a passport in your new name if you are planning to travel abroad. You can apply up to 3 months before your marriage or civil partnership ceremony. You must have given legal notice to be eligible.
Application forms must be sent to the Warwickshire office holding your ceremony booking, with a stamped addressed envelope for return.You are required to send this form with your new passport application. Your old passport will be cancelled, and your new passport is ‘post-dated’ – meaning you cannot use it before your ceremony date.
More information can be found at Gov.uk - Change your name or personal details on your passport.