C R.

This site costs a little more for their notify service (£28), but I found this to be more than money well spent. For someone who let their other half deal with all the admin stuff like sorting out banking and tax returns etc, DeedPollOffice takes you through the name change process quickly and with minimum fuss. I took care of everything in one afternoon, with the exception of the Passport, for which you need to show other docs which now possess your new name. Handily though, you can continue to travel with your old passport and old name, provided you complete all the bookings in your old name as well. You can simply change your passport when you're due a new one anyway.
You need to get the deed poll signed before completing any other steps, as you need to send copies to your Dr, Union, Bank etc.