If you think your company's telecom bill should bear the warning, "Read it and weep," try this number on for size: The average large corporate customer is probably paying as much as $8 million a year more than they should on telecommunications through a combination of faulty billings and missed savings opportunities. Now, there's an expense that would certainly make any finance executive choke up. Yet, according to Boston-based consultants The Aberdeen Group, this kind of bottom-line hemorrhaging is a reality when it comes to telecom spending, which amounts to about 3.6% of most companies' revenues.

The reasons behind this waste are complicated. The biggest, Aberdeen says, is the error rates in billing, generally in favor of the vendors, that run from 7% to 12% of total spending. That is coupled with the fact that, despite the high volume of mistakes, 85% of bills simply get paid, unaudited.

There are other explanations as well. "Lack of visibility into telecom service contracts, legacy billing systems rife with errors, and complexity caused by a period of telecom industry bankruptcies, M&A and new service offerings have made telecom costs hard to control," says Aberdeen analyst Rick Saia.