You have two profiles. There is one maintained by BT which a speed test at
http://speedtest.btwholesale.com/ will tell you if you choose the Further Diagnostics option after running the initial test. Then there is another one maintained by Plusnet which you can find out here
https://portal.plus.net/my.html?action=data_transfer_speed under Current Line Speed.
The two figures are meant to be the same but Plusnet cannot keep up with changes to the BT IP Profile and their profile often lags behind by some few days. The Plusnet profile serves no purpose unless you are trying to use your broadband connection beyond its full capacity with different types of traffic, which for many people is never. However it might be throttling your speed unnecessarily at the moment. Check and if so a request to Plusnet Tech Support should fix this.
