"640," N.J’s latest area code, goes into effect soon

New Jersey’s latest area code will go into effect in January.

With numbers in the 609 area code running out, the state’s Board of Public Utilities approved a request by Neustar, the Federal Communications Commission’s numbering plan administrator, to create the 640 area code earlier this year.

The new area code will be an overlay to 609, meaning that the area — stretching from Mercer County down toward the southeastern coast — will not be split and new numbers will be added as 640, according to Neustar.

The Board of Public Utilities provides the dialing procedures:

To complete calls from a 609 area code to another 609 area code telephone number, the new dialing procedure requires callers to dial the area code + telephone number. This means that all calls within the 609 area code that are currently dialed with seven digits will need to be dialed using ten digits, that is, the area code + telephone number. The same dialing procedures will apply to telephone numbers assigned to the new 640 area code.

In addition, calls made from the 609 area code to the 856 area code that are currently dialed with seven digits will need to be dialed using 1 + area code + telephone number. The same dialing changes will apply to calls made from the 856 area code to the 609 area code. Local calls made within the 856 area code can continue to be dialed with just seven digits.

The administrator says that numbers in the 609 area code will be exhausted by the third quarter of 2018.

Area code 640 will be the tenth in the state, joining 201, 551, 609, 732, 848, 856, 862, 908, and 973.

201 was the first area code assigned to New Jersey in 1947. It covered the entire state until 609 was added for South Jersey in 1958.

As demand increased through the decades, 908 was introduced in 1991, and the additional area codes followed due to the ubiquity of fax machines, pagers, and later cell phones.