Area Code 631 – New York | Cities, Time Zone & Details

Area Code 631 — New York

Covers Huntington, Babylon, Islip, Smithtown, and Brookhaven and surrounding areas in New York (NY).

Time zone: Eastern (ET)  |  Established: 1999

Where Is Area Code 631?

Area code 631 covers Suffolk County on eastern Long Island including Huntington, Babylon, and the Hamptons. Created in 1999 to handle growing demand for phone numbers, it serves approximately 1.5 million residents in the Eastern (ET) time zone.

Huntington is the largest city in the 631 area code and serves as the economic and cultural center of the region. Other notable communities include Babylon, Islip, and Smithtown, each contributing to the area’s mix of residential, commercial, and cultural activity. The region supports a diverse economy with opportunities in healthcare, education, retail, and various service industries.

New York is served by 19 area codes in total, reflecting the state’s population growth and demand for telephone numbers over the decades. Area code 631 was carved out in 1999 to address increasing number demand in the region, allowing each area to maintain a sufficient supply of available numbers.

Major Cities and Communities in the 631 Area Code

The following cities and communities are served by area code 631:

  • Huntington
  • Babylon
  • Islip
  • Smithtown
  • Brookhaven

Area Code 631 Details

StateNew York (NY)
Time ZoneEastern (ET) (UTC-5 / UTC-4 (DST))
Year Established1999
Overlay CodeNo
Approximate Population Served1,500,000
RegionCovers Suffolk County on eastern Long Island including Huntington, Babylon, and the Hamptons

Interesting Facts About Area Code 631

  • Area code 631 was created in 1999 when New York’s existing area codes could no longer meet the growing demand for new phone numbers in the region.
  • Area code 631 serves approximately 1.5 million residents in New York, centered around the Huntington area.
  • New York uses 19 area codes in total, reflecting its large population and the ongoing demand for telephone numbers.

Related Area Codes

Other New York area codes: 212, 315, 332, 347, 516, 518, 585, 607, 646, 680, 716, 718, 838, 845, 914, 917, 929, 934

Connecticut: 203, 860

Massachusetts: 413

New Jersey: 201, 973

Pennsylvania: 570, 717

Vermont: 802

Frequently Asked Questions

What cities use area code 631?

Area code 631 serves Huntington, Babylon, Islip, Smithtown, and Brookhaven and surrounding communities in New York.

What time zone is area code 631?

Area code 631 is in the Eastern (ET) time zone (UTC-5 / UTC-4 (DST)).

Is 631 a toll-free number?

No, area code 631 is not a toll-free number. It is a geographic area code assigned to New York. Toll-free area codes include 800, 888, 877, 866, 855, 844, and 833.

When was area code 631 established?

Area code 631 was established in 1999.

Other New York Area Codes

212  •  315  •  332  •  347  •  516  •  518  •  585  •  607  •  646  •  680  •  716  •  718  •  838  •  845  •  914  •  917  •  929  •  934