be necessary. An overlay of 615—which would be Tennessee's first overlay—was recommended. 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. The overlay code, 629, was approved on October 21, 2013. Permissive dialing began on July 26, 2014, during which it was possible to make calls with either seven or ten digits (the latter with the area code). Ten-digit dialing has been required in the 615/629 area since late February 2015; forgetting to add 615 or 629 first results in a recorded message reminding them. Nashville was one of the largest cities where seven-digit dialing was still possible. See also List of NANP area codes References External links 1954 establishments in Tennessee 2014 establishments in Tennessee 615 615 Telecommunications-related introductions in 1954