It seems telephone sales are doing so well that the phone companies are running out of numbers for the 717 area code, so the Pennsylvania Public Utilities Commission will be adding a 223 area code. Sometime this summer, probably in August, telephone callers in the 717 area will be required to dial all 10 digits including the area code, rather than only seven digits.
If your new neighbor obtains a new number, you may have to remember that 223 is not necessarily on the other side of the region; it’s next door. And the seven-digit number you are dialing is not in some other state. It’s across the street.