Area codes 516 and 363

File:New York State and surrounding areas Area codes Jan 2024.png: area codes 516 and 363 are highlighted in light brown.]]

Area codes 516 and 363 are telephone overlay area codes in the North American Numbering Plan (NANP) for the U.S. state of New York. The numbering plan area (NPA) comprises Nassau County on Long Island. Area code 516 was created in 1951 and 363 was added to the numbering plan area in 2023.

History

When the American Telephone and Telegraph Company (AT&T) established the first nationwide telephone numbering plan for Operator Toll Dialing in October 1947, Nassau and Suffolk counties, the lower Hudson Valley, and some areas adjacent were assigned area code 914. At the time, this area was largely coextensive with the New York state portion of the New York metropolitan area. In 1951, Nassau and Suffolk were designated as a separate numbering plan area (NPA) with area code 516.{{cite journal |last1=Mabbs |first1=Ralph |title=Nation-Wide Operator Toll Dialing—the Coming Way |journal=Bell Telephone Magazine |date=Winter 1947–1948 |volume=26 |issue=4 |page=181 |url=https://archive.org/details/sim_bell-telephone-magazine_winter-1947-1948_26_4/page/n5/ |access-date=2022-04-23}}

Despite Long Island's growth in both population and telephone service during the second half of the 20th century, this configuration remained for five decades. By the late 1990s, the proliferation of pagers and cell phones required further division to provide more telephone numbers for Long Island. On November 1, 1999, Suffolk was separated as a new numbering plan area with area code 631, while Nassau retained 516. Permissive dialing of 516 across Long Island continued until spring 2000.{{cite news|url=https://www.nytimes.com/1999/10/31/nyregion/suffolk-county-gears-up-for-631-area-code.html |title=Suffolk County Gears Up for 631 Area Code |last=Rather |first=John |date=October 31, 1999 |work=The New York Times}}

Prior to October 2021, area code 516 had telephone numbers assigned for the central office code 988. In 2020, 988 was designated nationwide as a dialing code for the National Suicide Prevention Lifeline, which created a conflict for exchanges that permit seven-digit dialing. This area code was therefore scheduled to transition to ten-digit dialing by October 24, 2021.{{cite web|url=https://nationalnanpa.com/pdf/PL_556.pdf|date=January 8, 2021|publisher=North American Numbering Plan Administrator |title=Transition to 10-digit dialing (for 988 as 3-digit access to National Suicide Prevention Hotline)|access-date=March 9, 2021}}

A 2021 NANP analysis of numbering resources projects exhaustion of NPA 516 during the second quarter of 2023.[https://www.nationalnanpa.com/reports/October%202021%20NPA%20Exhaust%20Analysis.pdf 2021 October NANPA Exhaust Projections] As a result, additional relief was expected. An overlay of 516 with a new area code was recommended, although a boundary-extension overlay was also considered which would have expanded area code 934 (overlaying 631) to also overlay 516.[https://documents.dps.ny.gov/public/Common/ViewDoc.aspx?DocRefId={483CD61D-C936-433B-9BAB-679F4606F3A5 New York State document] In January 2022, the new area code 363 was announced to overlay 516 on January 20, 2023.{{Cite web | url=https://www.areacodehelp.com/where/area_code_363.shtml | title=Area Code 363 - Details, official location, official service date, history and time zone }}{{Cite web|title=New area code for Nassau County will be 363, state says|url=https://www.newsday.com/long-island/nassau/new-area-code-363-1.50486188|access-date=2022-01-24|website=Newsday}}