Category Archive 'Area Codes':
Area Codes – A short history
The invention of the telephone number is probably as complex and convoluted as the origin of the machine itself. Going from operators patching calls between the – relatively few – consumers to letting an electronic machine handle the whole connection, there are lots of leaps and bounds which help form a bridge of connected dots and help us unravel the evolutionary process of the telephone service. The first major idea here is that of the area code, which came about with the advent of direct dialing in 1951.
Right from the start, area codes followed a pattern that was a legacy of the rotary-dial type of machine. The first assigned codes were to major cities spread across the continent. These always had a 0 or a 1 for middle digit to distinguish between an area code and an exchange code. The middle digits of the exchange code were never 0 or 1. This also helped create a logic flow for switching systems. However, over time, all the binary middle digit code combination were exhausted and the country had to start using other digits too as the middle digits. Another change was the mandatory trunk code which again meant more room per area codes.