Chris Browne wrote:
> I'm pretty sure that they _don't_ track balance updates for each
> transaction that applies to a customer's account. You could, via one
> form of trickery or another, "overdraw" your account by a fairly hefty
> amount, and they probably won't notice for a day or even three. But
> once they notice/estimate that the Gentle Caller has built up some
> dangerously high balance, they'll warn of impending discontinuation of
> service if some sum isn't paid by some date.
This works for companies that have some degree of power over their
customers. E.g. pay up or we disconnect your service. Return your
overdrafts/pay your fees or we mess up your credit.
This doesn't work if it's a small company who's account has been
emptied. Sure the bank will refuse to honor the check but then that
company will be hit with overdraw penalties and possible legal penalties
to the payee for the bounced check.
The warning threshold system is easy to implement but there will always
be corner cases where the warning is not soon enough or a single payment
wipes out ~ 100% of the account. Warn too often and it'll be ignored by
people as a "boy crying wolf" alarm.