It seems easy enough to add or remove members on Bivio's
site, but what needs to be done to make this right with the
IRS?

Randy, if you have ever had transactions, meaning payments followed by a
withdrawal, do NOT delete/totally remove members. They should be placed on
the inactive or withdrawn list. Are you sure bivio will even let you
totally delete a member with previous transactions? I know CAO online
won't. Gene Rooks