Telephone message accounting system

Claim 1

In a telephone system, an office having: a. a plurality of line circuits, b. a plurality of trunk circuits, at least one of said trunk circuits being a remote station trunk circuit adapted to be connected to an office lacking billing equipment, others of said trunk circuits being inter-office trunk circuits adapted to be connected to offices having billing equipment, c. number receiving means adapted to receive digit information, d. switching means for connecting a calling line or trunk circuit to said number receiving means for the latter to receive called number information, e. automatic message accounting means for recording call charge information, f. each trunk circuit including identity means, g. a call identity indexer connected to said identity means of each trunk and to said automatic message accounting means and responsive to operation of said identity means in a trunk circuit for identifying such trunk circuit to said automatic message accounting means, h. said one trunk circuit including operating means responsive to connection of said number receiving means thereto to operate said identity means of said one trunk circuit during a call from said one trunk circuit but not during a call to said one trunk circuit, and said inter-office trunk circuits lacking said operating means, i. said switching means including local circuit means operative upon connection of said switching means to a said line circuit, and means for connecting said local circuit means to a trunk circuit upon a call for such line circuit to such trunk circuit, j. each said trunk circuit including means responsive to connection of said operated local circuit means thereto for operating said identity means of such trunk circuit, whereby to cause such trunk circuit to be identified to said automatic message accounting means.