After the 14th February 2007 it has become easier for UK broadband users to switch Internet Service Providers. ISPs are no longer allowed to charge a fee for switching accounts, and they can be fined if they obstruct the process. More
I had an account with BT, but I was very dissatisfied with their service. BT is the biggest broadband provider in the UK, but Which magazine shows their customer approval ratings at 34%, compared with Waitrose and Zen which have ratings in the high 70s.
Most of the Waitrose web site is clearly set out and full of information. For example, you can check your download speed at any time. You can also see how much you have downloaded to date, and all your billing. This is all information that should have been on the BT website, but wasn't. Also, Waitrose give all the profits from their ISP operation to charity, and when you enroll you get to vote on which charity is going to get money. A final selling point was that Waitrose is owned by the JOhn Lewis Partnership, which is a workers cooperative.
Switching from BT is easy. All you have to do is get a number called a Migration Authorisation Codes (MAC) from BT, and paste it in a form at your new ISP.
The only problem I incurred was finding out how to get my MAC address from BT. After about twenty minutes of fruitless clicking on the BT site I finally found this page. Just click on 'Moving my connection from or to BT' and complete the form. I got an email with my MAC address the following day.
A final point is that if you bought your modem or router from BT it may be locked so that it only works with BT Broadband. Your new ISP will be able to advise and supply new kit.
Added 1st October 2008
You could also try calling either of these numbers
0800 800 030
0800 328 6738