A History of Telephone Numbers

Updated: Feb 14

A timeline of how telephone numbers came to be.

Alexander Graham Bell testing an early prototype in 1876


Operators and Switchboards


Back in the 1920s, if you wanted to call someone, you would pick up the phone and say 2 letters followed by 5 digits (2L-5N format). On the other end would be an operator who would then use a switchboard to connect you to the right person. Phone calls were all routed through a call exchange composed of several operators (typically women) using switchboards to connect callers.


Call exchanges were distributed throughout the country and handled all the local calls for their corresponding regions. For this reason, local calls were easier to make than long-distance calls.


Calling a friend from your local area was easy; you would pick up the phone, tell the operator the number of your friend, and they would patch you over. However, if you wanted to call someone from California and you were in New York, you would have to cross several operators before your final call was connected.





The Evolution of Telephone Numbers


Before the 1950s, telephone numbers abided by the 2L-5N format. The two letters in the 2L-5N format represented the closest call exchange, and five numbers were the associated phone number.


As the telephone system expanded across the United States, the need for new numbers quickly grew. As a result, area codes were officially introduced in 1951 to keep up with the growing demand - the first being for the 201 for the state of New Jersey.


With the introduction of area codes, the 2L-5D format was scraped for the 10 digit standard we use today.




Modern Day Phone Numbers


With the invention of the internet came the possibility to "virtualize" a telephone number. By virtualization, we mean the ability to upload a number digitally and then make or receive calls from an internet connection. This is referred to as Voice Over Internet Protocol (VOIP) and utilized by thousands of businesses and residential customers in the United States.


With the invention of VOIP, uses for a telephone number expanded. For example, today, one can upload a telephone number to a VOIP service and have all calls forwarded to another cell phone number.


This is a common service for folks who have had a landline number for decades and are leaving their old carrier but don't want to lose the number they've had for years.


The Power of a Landline Number


Do you have a landline number? If so, did you know that you own your number, not your carrier. At NumberDock, we specialize in empowering landline numbers. Learn what your number can do by visiting our homepage!



Thanks for reading! If you have any questions please don't hesitate to contact us or email us at help@numberdock.org.