In automatic direct outward telephone dialing, a digit, often a 1, or a 9, that (a) enables access to an outside facility, e.g., a PBX or local exchange, and (b) is prefixed to the specific number being dialed. Note 1: Throughout the United States, an access digit, usually 1, must be prefixed to an area code before dialing the area code and the specific number to which a connection is desired. Note 2: The access digit 9 is often used to establish a connection between a PBX and a local exchange.