Nassau's new 363 area code expected to go into service in January

363 could come 1/20/23.

Nassau County’s soon-to-be area code, 363, is scheduled to go into service as early as Jan. 20, 2023.

That’s according to a planning memo posted Thursday by the North American Numbering Plan Administrator, which rolls out new area codes and sets the rules for how phone numbers are assigned.

The new area code, which was announced Jan. 24, is needed because available 10-digit numbers in 516 are set to be depleted by the second quarter of 2023.

Only when new 516 numbers are used up will the 363 numbers go live, said Heidi Wayman, a manager for the North American Numbering Plan Administrator. Jan. 20, she said, is the earliest planned date for the exhaustion.

Those with 516 will keep that area code, but in what is known as an "overlay," requesting new service, an additional line, or a move in the location of service, might each be met with a seven-digit phone number with the area code 363.

The addition of the area code is meant to provide "numbering relief," according to the state Public Service Commission.

Word that Nassau County would be getting a new area code came last fall, in an announcement by the commission. The 516 area code has been on Long Island for at least 60 years, and until 1999 serviced the entire Island.

That year, the Island was split into two, with Nassau keeping 516 and Suffolk getting 631. Suffolk got 934 in 2016.

The industry tries to avoid activating more than one new area code in the United States at the same time, Wayman said.

Nassau is on track to get the United States' first new area code of 2023, she said.

Coming immediately before that is expected to be North Carolina, where 472 is to supplement the existing 910, beginning Oct. 7, the last new one of this year.

After 363 goes into effect, Missouri is to get 975 to supplement existing 816, on Feb. 10, and Illinois 861 to supplement 309, on Feb. 24.

Later this year, a new suicide-prevention hotline, 988, is coming to the United States. By July 16, 2022, 988 joins other three-digit hotlines, such as "911" for emergencies, "411" for directory information and "311" in some localities for municipal services.

By Matthew Chayes

matthew.chayes@newsday.comchayesmatthew

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