363 area code launches Friday in Nassau County, joining 516

Nassau County's new area code debuts Friday, adding 363 to 516.

It's an effort to provide "numbering relief," says the New York State Public Service Commission, as the availability of 516-prefixed numbers rapidly diminishes.

The new area code is available to be assigned upon a request for new phone service, an additional phone line, or upon a move to or within the county.

The 363 area code joins 631, which in 1999 became Suffolk’s — splitting off from what was then the Long Islandwide area code of 516. Then, in 2016, Suffolk got a second area code — 934.

As with 934 — but unlike with 631 — the plan involves an overlay, in which existing phone numbers and lines keep 516. (Back in 1999, all Suffolk phones lost 516 and had to be dialed with 631).

“An overlay does not require customers to change their existing area code, but does require customers to dial the area code to complete local calls,” Verizon wrote in a news release Wednesday.

The price of a call will not change, and three digits can still be dialed for emergencies (911), suicide prevention (988), information (411) and (in some jurisdictions) nonemergency government services (311).

The 363 area code was announced In January 2022 by the Public Service Commission, which said the new code would apply to residential, business, wireless and other services.

Based on commission predictions, the new area should unlock enough new seven-digit phone numbers for Nassau for about 49 years.

“With the addition of the new area code, Nassau County is now well-positioned to accommodate future economic growth and to satisfy growing consumer demand,” a commission release Jan. 13 said.

It’s not certain, though, that any new numbers will be assigned to customers beginning Friday, only that there’s a possibility.

“Numbers in the 363-area code will not be available for assignment until remaining numbers in the 516-area code are exhausted,” the commission said.

That’s because while the North American Numbering Plan Administrator could run out of prefixes — the first three digits of a phone number after the area code — to assign to carriers, carriers might still have some 516 numbers in inventory.

In October 2021, that exhaustion was forecast to happen sometime in June 2023, according to Heidi Wayman, a manager working for the North American Numbering Plan Administrator, which rolls out new area codes whenever numbers within the existing supply are exhausted.

Wayman made the prediction to Newsday in October 2021.

Why the need for more numbers?

Blame demand for more and more phone numbers over the years — these days, not just traditional house phones, but Wi-Fi hot spots, OnStar, fax machines, security alarm systems and more.

As the commission put it: “Need for New Area Code Sends Strong Signal About Good Health of Local Economy.”

By Matthew Chayes

matthew.chayes@newsday.comchayesmatthew

Matthew Chayes, a Newsday reporter since 2007, covers New York City.