I recently moved ADSL and phone from BT to Plusnet Business.
The phone switch over was painless.
The phone service does almost all I want of it, with the addition of the CLI extra and activation of voice mail. I do slightly miss the BT facility of sending a SMS message to a linked mobile when voice mail is left, which can then phone home and listen to the voice mail.
On line access to call and billing information is far easier and faster than BT's dreadful system, which I have been unable to log on to for months. If you cannot log on to see them, paperless bills are invisible. At least the BT final bills came on paper.
As Roberto says, do investigate the availability and costs of any options you want.
Edited by awontroba (Thu 11-Sep-14 13:50:47)