How to let a user expire

Robin Galyan ( )
Mon, 14 Apr 1997 12:58:46 -0400

So, I have a user that wants to expire at the end of the month.
How do I tell emerald to NOT bill them or renew them after a certain

I could write it down someplace, then on billing day try to remember to
delete them first, but gads, that seems archaic!