Kentucky regulators say a new area code for the western part of the state will overlap the existing 270 area code.
The Public Service Commission said Monday the "overlay" option for the new 364 area code is the least disruptive for customers and imposes the least cost on businesses. This is the first time two area codes will mingle in the same area in Kentucky.
For people living in the 270 area code, the decision means local calls will require 10-digit dialing that includes the area code. Long-distance calls will require 11-digit dialing that includes 1 plus the area code and then the seven-digit number.
Mandatory 10-digit dialing takes effect on Feb. 1, 2014.
The growing use of cell phones resulted in nearly all the numbers available in the 270 area code being taken.