615 area code numbers are in short supply. Of the nine million possible number combinations, they are all expected to be used by 2015.
"Certain areas run out of numbers faster than other areas," explained TRA Chief of Utilities David Foster. "Nashville is growing so much and they use so many numbers."
Officials also blame the shortage of remaining 615 phone numbers to emerging technology.
Twenty years ago, Foster said a family of four would share one home phone, but in 2013 that has changed dramatically due to cell phones.
"A family of four or five, they could have a home telephone, and they could have four or five cell phone numbers," he said.
Online numbers have also ramped up the use of phone numbers as well.
Skype allows each user to reserve up to 10 phone numbers, while Google has purchased thousands of 615 numbers for its Google Voice customers.
On top of that, pre-paid phones use tens of thousands 615 area code numbers.
Due to the shortages, the TRA said they will add a new area code to Middle Tennessee.
Currently, Williamson, Wilson, Sumner, Rutherford, Trousdale, Davidson, Cheatham and nine other counties use the 615 area code.
The number of counties using the 615 area code could change under one of two options the TRA is considering.
The first option, called an overlay, would create a new area code which would be given to all new phone numbers being added to the area. All current 615 users would be able to keep their current number.
The second option, a geographic split, would divide the 615 area into two area codes. Approximately half of wireless and landline users currently using the 615 area code would be required to change their telephone numbers.
When asking locals their opinion, News 2 encountered several who do not wish to see their 615 area code changed.
"People are already dialing 10 digits right now as it is. Where it will matter is if they have to get a new number," Beth Brinker said, adding that getting a new number would be inconvenient.
"I think I lean toward everyone keeping 615, but having to dial the full set of numbers," said Clifford Anderson.
"I want to keep my number," said Teresa Tippens. "It's like a social security number. You get attached to it."
The 615 area code was introduced to Tennessee in 1954 and is projected to run out of available phone numbers by the second quarter of 2015.