Currently, users are presented on their account page with a table that displays their current recurring fee, time of next payment, and a link to cancel the recurring fee.
Rather than a "cancel" link, I think this would be much better if this was an "on/off" toggle. We occasionally have users who subscribe to our site, decide they want to stop the account auto-renew, then tell us two weeks later they wish to restart their auto-renewal. It would be more appropriate if this capability was in the hands of end users.
I would think this should be fairly simple to implement. Just add another column to the table storing the recurring fees as an "on/off" flag, and check this at the time of expiration.