A conference call is a telephone call in which the calling party wishes to have more than one called party listen in to the audio portion of the call. The conference calls may be designed to allow the called party to participate during the call, or the call may be set up so that the called party merely listens into the call and cannot speak. It is sometimes called ATC (audio tele-conference).

Conference calls can be designed so that the calling party calls the other participants and adds them to the call; however, participants are usually able to call into the conference call themselves by dialling a telephone number that connects to a “conference bridge” (a specialized type of equipment that links telephone lines).

Businesses use conference calls daily to meet with remote parties, both internally and outside of their company. Common applications are client meetings or sales presentations, project meetings and updates, regular team meetings, training classes and communication to employees who work in different locations. Conference calling is viewed as a primary means of cutting travel costs and allowing workers to be more productive by not having to go out-of-office for meetings.