Murfreesboro, Franklin, Brentwood, Gallatin, Hendersonville, and Lebanon are other major cities in the 615/629 service territory.
Although this was intended to be a long-term solution, within a year 615 was nearing exhaustion due to the rapid growth of the Nashville area, as well as the proliferation of cell phones and pagers.
[1] The TRA and telecommunications providers implemented several number conservation measures[1] that succeeded in averting the predicted crisis.
In 2003 the NANPA notified the TRA that the area code was not projected to exhaust its supply of numbers for at least five years.
[5][6] The decision to implement the new area code as an overlay, rather than a split, was made to spare Nashville-area residents and businesses the expense and burden of having to change their numbers, which would have required en masse reprogramming of cell phones.