A method for operating an integrated communications system providing voice and data communications to a plurality of users and simulating a key system. An outside line appearance is provided on a telephone coupled to the system; the outside line appearance is associated with a predetermined outside telecommunications trunk and has associated therewith a button and a lighting implement. In response to activation of the button, a lighting condition of the lighting implement is changed and a dial tone to the telephone by the integrated system. Digits are entered by a user depressing keys on the telephone and collected by the system. Restriction rule are applied to determine if a telephone number dialed by the user is restricted, and if restricted an error tone is provided. Caller ID information may be determined for the user. A determination is made as to whether the outside telecommunications trunk is available, and if not available an error indication is provided, and if available the caller ID information is applied and a call is initiated via the predetermined outside telecommunications trunk. Upon completion of the call, call statistics for the call in the integrated system are recorded within the system. The integrated system simulates a key system for the user and the particular telecommunications trunk, wherein for other users the integrates provided PBX telephone services.