<P> In seven - digit dialing , only the central office code and the station number is dialed , indicating that the call destination is within the local area code . This was the standard in most of North America from the 1950s onward . In some small villages with only one local exchange , it may have been permissible to dial only the four - digit station number . </P>
<P> In seven - digit dialing , only the central office code and the station number is dialed , indicating that the call destination is within the local area code . This was the standard in most of North America from the 1950s onward . In some small villages with only one local exchange , it may have been permissible to dial only the four - digit station number . </P>
when did phone numbers change to 7 digits
when did phone numbers change to 7 digits
from the 1950s onward
from the 1950s onward