Abstract: A method of providing multi-switch business group (MBG) services at each of a plurality of locations is described. The MBG services can be provided for calls made from a calling party served by an originating switch at one location to a called party served by a terminating switch at a location serviced by an inter-exchange carrier (IEC). When the calling party goes off-hook, a determination is made of whether the call is made from a centrex line. Digits dialed by the calling party are then collected at the originating switch. A determination is then made of whether the dialed digits contain an access code indicative that the call is to be routed to one of the plurality of locations which is served by an IEC. If the call is to be routed via an IEC, the initial address message (IAM) required for IEC calls, is modified to include MBG service information. This will permit MBG services to be offered between the calling party and the called party over public CCS7 trunks routed via an IEC.