to the site
From what I understand all your recordings are linked to your card and you will need to have that in the box to watch anything. It's the same if you record a movie and then cancel Sky Movies, you won't be able to watch it unless you are subscribed to the channel.
It does seem a bit strange to have to cancel one contract and send another
card out, almost as if they want to show they are getting more 'new' customers each quarter (tin foil hat at the ready)