Why can I receive quotes from some suppliers, but not complete the switching process with them on your site?

The energy supplier comparison service you are using has been provided by Which? Switch.

We are not able to switch you to suppliers that do not have switching arrangements in place with us. However, unlike other switching sites, Which? Switch compares prices from all energy suppliers, not just those which we have switching arrangements with. 

If we don't have a switching agreement in place with the energy supplier you have chosen, we'll provide you with a telephone number for the energy company so you can switch direct.