In telecommunication, a dial plan (or dialing plan) establishes the permitted sequences of digits dialed by telephone subscriber and the manner in which a telephone switch interprets these digits within the definitions of the prevailing telephone numbering plan. Dial plans in the public switched telephone network referred to as dialing procedures.
The collection of permissible digit patterns, so called digit-maps, for a private telephone system or for customer premise equipment, such as an analog telephone adapter (ATA) or an IP phone, is sometimes also called dial plan. A pattern may be as short as a single digit, e.g. for reaching an operator, or as long as a complete international telephone number, including trunk prefixes and international prefixes.