An N11 code or N11 number (said as n-one-one) is a special abbreviated dialing telephone number within the North American Numbering Plan, which allows access to special services. Each of these eight numbers prevents 10,000 telephone numbers (from N11-0000 to N11-9999) from being used. Only non-geographic area codes, such as toll-free 800/888/877/866/855/844 numbers and 900 numbers may use N11 as the telephone exchange prefix, since the area code must always be dialed for these numbers.
Usage is generally assigned as follows:
9-1-1 and 4-1-1 work from nearly every telephone in the U.S. and Canada, while the others vary from place to place. Generally, only 4-1-1 calls incur a fee. 9-1-1 access is mandated by law. 6-1-1 (formerly 8-1-1) with some traditional land-line telephone companies may also be accessible to activate service on such lines. Carolina Digital Phones can not be activated automatically and must be registered with our Customer Service Team.
Likewise, local or state/provincial government may or may not operate traffic information through 5-1-1. 8-1-1 was made mandatory in the U.S. in 2007, as is 7-1-1. Unlike 9-1-1, these may or may not be available on a phone without paid service.
0-1-1 followed by a country code is used to dial internationally, but this use is not considered an N11 code. 1-1-1 is not available in the NANP, because 11 is the prefix used to access vertical service codes from rotary phones, and is essentially meaningless to the system otherwise.