When did phone numbers change to 7 digits?
multipleQAs
When did North American plan to change all phone numbers to 7 digits get accepted? When was the first new area code received by a locale, an indication of when North American phone numbers changed to 7 digits? When was the first customer call using the NANP made, an indication of when North American phone numbers changed to 7 digits?
October 1947
1947
November 10, 1951
Telephone numbers in the Americas North American Numbering Plan
american phone numbers digits
North American Numbering Plan Telephone numbers in the Americas National conventions for writing telephone numbers Telephone number List of mobile telephone prefixes by country Telephone numbers in Canada Ten-digit dialing List of North American Numbering Plan area codes Seven-digit dialing Area code 868
Each three-<b>digit</b> area code has a capacity of 7,919,900 <b>telephone numbers</b>: NXX 
may begin only with the <b>digits</b> [2–9],&nbsp;... All countries in the <b>Americas</b> use codes that start with &quot;5&quot; except for: Canada, the 
United States ... All geographical <b>numbers</b> have 8 <b>digits</b>: Venezuela, South, +58&nbsp;... The national conventions for writing <b>telephone numbers</b> vary by country. While 
international ... <b>Telephone numbers</b> in China are 10 or 11 <b>digits</b> long (excluding 
an initial zero which is required at times) and fall in at least four distinct 
categories: ... This <b>number</b> format is very similar to the North <b>American</b> numbering 
plan, but&nbsp;... For example, a <b>telephone number</b> in North <b>America</b> consists of a three-<b>digit</b> area 
code, a three-<b>digit</b> central office code, and four <b>digits</b> for the line <b>number</b>. <b>American</b> Samoa, +1, 684, 10, NANP member, <b>no mobile</b>-specific prefix ... Many 
exchange codes contain primarily <b>mobile</b> devices; local <b>numbers</b> are portable 
between ... <b>Mobile numbers</b> are 7 <b>digits</b> long, and look like this: +36 XX 123 4567
. Toll calls from Canada to other North <b>American</b> Numbering Plan countries are 
dialled in the same format (eleven <b>digits</b>) as domestic calls. Overseas calls to&nbsp;... In the United States and Canada, ten-<b>digit</b> dialing is the practice of including the 
area code of a <b>telephone number</b> when dialing to initiate a <b>telephone</b> call. When 
necessary, a ten-<b>digit number</b> may be prefixed with the trunk code 1, ... After the 
implementation of the North <b>American</b> Numbering Plan, placing a local call within
&nbsp;... Each area is assigned a three-<b>digit</b> area code which is prefixed to each 
<b>telephone number</b> issued in its service area. Some areas are assigned multiple 
codes in&nbsp;... Seven-<b>digit</b> dialing is a <b>telephone</b> dialing procedure customary in the territories of 
the North <b>American</b> Numbering Plan, for dialing <b>telephone numbers</b> in the&nbsp;... The area code 868 is assigned to Trinidad and Tobago, a member of the North 
<b>American</b> Numbering Plan (NANP). The <b>telephone</b> numbering plan for the 
country is known as the National Numbering Plan. It is part of a system used for 
assigning <b>telephone numbers</b> in Trinidad and ... Callers must simply dial 1 + 868 
+ seven <b>digit phone number</b>.
from the 1950s onward
Seven-digit dialing