the 7 digit phone number started on february 16, 1968.
when did the 7 digit phone number start?
february 16, 1968
in 1950, new york city's five boroughs were dialed from various communities in new jersey with the digits '1-1' followed by the 7 digit telephone number. while new york city was assigned area code 212 at the very beginning of the area code format in october 1947, it wouldn't be until later in the 1950s when englewood, new jersey, customers would dial their calls to new york city using the digits 2-1-2. the use of the '11+' code from englewood (and other parts of northeastern new jersey) to call new york city had been in place for a while, even prior to 1951. new york city's five boroughs also had been dialing northeastern new jersey as 11+ the two letters and five digits of the new jersey number as well for a while prior to 1951 and until the latter 1950s.
at&t communications
within the nanp, a leading digit of 0 or 1 indicates special dialing arrangements. for example, 0-1-1 followed by a country code is used to dial internationally or 1 followed by a ten-digit phone number indicating long distance or toll charges. in a few states, some areas retain the ability to use seven-digit dialing for local calls; in these areas a leading digit of 1- must be followed by a ten-digit phone number. as such, n11s are restricted by nanp design to n values 2 through 9, creating the eight allowable n11s. this is also why npas (area codes) or seven-digit phone numbers (designated by nxx-xxxx) cannot have a 0 or 1 as the first digit (n).
n11 code