Abstract: An automatic dialer is accessible to the public network directly or via a PBX. During registration mode, a controller is responsive to a unique keystroke input to store a binary 1 as a call identifier and a destination terminal number of the public network into a first storage location of a memory or store a binary 0 as a call identifier and a destination terminal number of the PBX into a second storage location of the memory. During call establishment mode, the controller is responsive to a replica of the unique keystroke input to recall data from a different location of the memory. When the dialer is connected to the PBX, the controller dials a network access digit, inserts a pause and dials the recalled destination terminal number if the recalled call identifier is binary 1 or only dials the recalled destination terminal number if the recalled call identifier is binary 0.