I think, at least when I unregistered, you had to call them to cancel...I'll have a look. /Edit You still do! http://experian.metafaq.com/templat...ftvst:topicID=$&id=LOHURKI8BFOEO10D65LS5RM90I
If you phone them, be prepared to sit and wait (and get charged for the call costs). Calling is the only way to ensure you've cancelled. The rest is organised in such a way it's impossible to work out how to cancel. A very unsavoury business practice. After cancellation you'll get an email confirming you've cancelled.
I too have to say that calling was absolutely no problem at all. Called up and said I'd like to cancel. They asked what my reason for cancelling was. I said that I wanted to get my credit score and that I wasn't using the monthly features enough to make it worthwhile. Confirmed cancellation. I asked for her name - she was happy to give it to me. Total time spent on the phone - around 3-4 minutes and job done.
The call service is usually no problem but I still get emails from them trying to get me to sign up again!!