If you already have fibre installed, you won't need an engineer to switch to a new fibre connection — unless you are upgrading to full fibre. The same goes for if you're currently on a copper ADSL broadband connection. Most fibre deals use the same copper wires as your phone line, so you also don't need an engineer to switch to those. But if you want full fibre, you'll need an engineer to install a fibre cable at your property.