BT Line Checker is king.
Result for a line on that exchange.
For Telephone Number 01475637336 on Exchange GOUROCK
Your exchange is ADSL enabled, and our initial test on your line indicates that your line should be able to have an ADSL broadband service that provides a fixed line speed up to 2Mbps.
Our test also indicates that your line currently supports an estimated ADSL Max broadband line speed of 7Mbps.
Your exchange is planned to have ADSL2+ by 31st January 2011. Our test also indicates that your line currently supports an estimated ADSL2+ broadband line speed of 14Mbps. Our test also indicates that your line could support an estimated ADSL 2+ Annex-M broadband upstream line speed of 750Kbps and downstream line speed of 5.5Mbps.
The actual stable line speed supportable will be determined during the first 10 days of use. This speed may change over time, to ensure line stability is maintained.
If you decide to place an order, a further test will be performed to confirm if your line is suitable for the service you wish to purchase.
Thank you for your interest.
Please note that dates and exchanges are indicative and subject to change.
BT Line checker can be found here - http://www.dslchecker.bt.com/adsl/adslchecker.welcome