A numerical appendage to a main telephone number that directs a call to a specific individual or department within an organization. For instance, calling a business’s main number and then dialing “101” connects the caller directly to the sales department.
This routing mechanism enhances internal communication efficiency and external caller experience. By avoiding the need for a receptionist to manually transfer each call, extensions streamline the process of connecting with the desired party. Historically, it developed alongside the growth of PBX (Private Branch Exchange) systems, enabling complex call management within larger entities.