Answer
I work for bt and if you check bt.com/broadband it will give you a checker on there, postcode or non-cable telephone number required, you can get a rough idea what you can get, i can inform you that we are upgrading lines over the next few years to fibre-optic that will give speeds of upto 24meg, the main reason you can only get low speed at present would be distance from the exchange or line quality, also the line ends at the termination point i.e. where it plugs in, so if you have an extension over 7m long you would also get problems as the quality of extension vary and overall is not
the same quality as outside line plant obviously, hope this helps, rob
