Portions of New Jersey will soon be getting a new area code. 

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

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

"The New Jersey Board of Public Utilities has directed all local exchange service providers to activate the new area code to ensure the availability of numbering resources in a manner that is most efficient and least confusing for consumers, while minimizing possible disruption to consumers and businesses," a Neustar news release states. 

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.