MikeBz: Could we have taken out a line rental only contract? Didn't even consider that since it's £10.50 a month whatever and we knew we were committed to paying that. Charging an extra £14.XX a month on top of that £10.50 just to not have something which was free anyway is robbery whatever the T&Cs say. It's a fact that putting whatever you like deep in the small print of your T&Cs doesn't mean that by definition it's OK, fair, legal, or good business practice.
The icing on the cake? To get out of the line rental contract, should you wish to, it costs a max of £70 even though a year's line rental is £126.
Mike
If you were to move your line rental within the first 12 months then the £70 fee kicks in. This was introduced to stop customers using BT to install a new line then to go to Talktalk who won't install new lines. Same goes for the Call Packages where you could get cheaper calls via Tiscali or Talktalk or Primus CPS.
With BT you have to take a call package although the "Unlimited weekend Plan" and "Unlimited Evening & Weekend Plan (with 12 month rolling contract)" are both free with minimum terms.
Not sure about being hidden, the BT website is covered in T&Cs asterisks etc..
If you had gone with The Phone Co-op for instance line installation is cheaper and although there is still a 12 month line rental contract for new lines their call packages seem to be only 3 months minimum. The Post Office doesn't seem to have a minimum line rental term for new installs as far as I can see.