Standard charges for ISDN service include installation and monthly service and usage charges. Other charges may cover inside wiring, time and materials, foreign exchange, and special assembly. The phone company will quote pricing for installation, monthly charges and usage charges. They will not quote labor, time and materials. These may show up as extra costs on your bill.
Phone companies charge federally mandated tariffs for ISDN service.
However, by the time you get your first bill, the tariffs in your state may have changed. If you feel as though a mistake has been made, call the billing number listed on your bill. Be prepared to supply pricing information your phone company gave you when you ordered your service. Use the top ten ISDN Troubleshooting Guide to help you isolate ISDN phone service problems.