As you are all probably aware by now, I am a bit cynical about such companies or corporations giving ANYTHING away that they don't need to.
This tariff has a few very strange connections to it !
Obviously you need to be VERY poor to get it as there is a list of benefits that you have to be on before you will be considered for this tariff.
I wonder if this tariff is being subsidised by the government so that BT, ( who never give anything away for nothing in my experience ), can do it and look like goodie-goodies as they do it.
Maybe it would be a good thing to really look at all of the ins and outs of this tariff before trying to commit to it.
To this end
HERE is a download of the PDF version of the guide to this "too good to be true" tariff.
( BTW.... you will need to have Acrobat Reader resident on your computer to be able to read it. You can get it
HERE for free, but be careful to untick the little box offered if you do not want the Google toolbar to come with it ).