You may have to add an area code or dial 1 from certain areas.
The 640 area code has been added to the region currently served by area code 609. This process is known as an area code overlay and requires a new dialing procedure. Your existing area code will not change, but you will be required to dial the area code and the seven-digit telephone number on calls within the same area code. There are instances where certain calls may require dialing a 1.
