ABSTRACT: This Volume is the last in a six volume set that documents guidelines for carrier access billing. It contains definitions for the data elements presented on the Billing Data Tape (and documented in Volume 3 [SR-1872]). Data source, characteristics, default values, valid entries, type of account, associated records and an example for each data element is also included. NOTE: The updates contained is this issue is a correction to the record association on data element Service Center Contact Number.