Major service providers offer telecom expense management (TEM) services of one kind or another. Such offerings purport to let customers monitor and track telecom expenses for their wireline and wireless services.
In other words, the service providers have a TEM service that charges their customers for tools that are designed to find mistakes made by their own billing systems - a humorous proposition - at best.
The services are marketed on the premise that they will help customers save time and money. Questions for clients to consider include: Why are the bills wrong in the first place? Why do they need to pay their supplier to validate or invalidate their own bills? Why will the accuracy of this service be any more accurate than the bill itself?
Protect your own interests... best practices demand an independent source for TEM information and analysis.

