For an explanation of how TBA works, here are some screen shots and descriptions:
Main Screen
Main Screen - more
Customer Master
Invoices
Pager Inventory
Payments
Report Preview
Resource
Mailing Labels
Misc Entry
Startel Import
Amtelco Import
Axon Import

The Billing Assistant

Version 4.0 is the latest in the fourteen year evolution of the product.  

Click on the links to the right to see how easy billing can be.