No it doesnt. There is no continuing cost of the line for BT at all. Once its in thats it. BT dont have to do anything for the upkeep of the phone line there is zero running cost. This is from your house to the exchange I`m talking about which is what this Line Rental Charge is for. When was the last time you saw BT come out and do maintenance upkeep on your line ?
Years ago when Mercury were bought over or going bust there was talk of forcing BT to scrap the line rental charge but for some reason Ofcom lost and BT won cant remember the details. It was proven then that line rental charge was a very small percentage of the profit BT achieve and they could actually do away with it and not make much difference to their profit.
Sorry will stop now this is off topic.
What about maintenance of the exchange? (The actual fabric of the building and equipment inside), electricity consumption, maintenance of the cabinets and general infrastructure such as the grids you see in the pavement? Investment in new technologies?
I think to view the line rental charge as simply paying for the line that has been supplying your house for X number of years is quite a naive way of looking at it.