A friend of mine is moving to a house on a newly built housing estate and has been told by the company he is buying the house from he can't have his BT service transferred to the new house as there is only one company running phone services on this estate. A company called Seethelight.

http://www.seethelight.co.uk/phone.php

Does anyone on here know if they are any good? Or can you run a BT service on their lines?

It's a fibre optic service - apparently unlimited up to 200Mb broadband and phone packages appear competitive, if not better than BT. A BT service cannot be run over the fibre because it won't connect to a BT exchange; it will instead connect to Seethelight's network.

I had never heard of them until you posted so cannot comment on what they're like.