Babylon, New York

Where Is Area Code 631?

Area code 631 serves Suffolk County on Long Island in southeastern New York. It covers the eastern and central part of Long Island, while neighboring Nassau County uses different area codes. Babylon is one of the communities within this area code.

Area code 631 includes many Suffolk County communities, including Babylon, Huntington, Islip, Smithtown, Brookhaven, Riverhead, and Southampton. It also serves places such as Patchogue, Brentwood, Deer Park, and West Babylon. The area code reaches both busy suburban areas and smaller East End communities.

Area code 631 covers notable Long Island features such as the Atlantic Ocean shoreline, the Long Island Sound shoreline, and the Hamptons on the South Fork. Fire Island lies just off Suffolk County’s south shore. The area also includes major sites such as Long Island MacArthur Airport in Ronkonkoma and Stony Brook University in Stony Brook.

History of Area Code 631

Area code 631 began service on November 1, 1999. It was created in a split from area code 516, which had served all of Long Island before the change. After the split, 631 became the area code for Suffolk County, while 516 remained in Nassau County.

Area code 934 was added as an overlay to 631 on July 1, 2016. The overlay was approved because Suffolk County needed more telephone numbers as demand grew for cell phones, fax lines, and other services. Since that overlay, new numbers in the same area may use either 631 or 934.

Key Facts About Area Code 631

• Area code 631 is in New York State and serves Suffolk County, including Babylon on Long Island.
• Area code 631 is in the Eastern Time Zone.
• Area code 631 was created on November 1, 1999, in a split from area code 516.
• Area code 934 overlays area code 631, and the overlay took effect on July 1, 2016.
• Suffolk County had a population of 1,525,920 in the 2020 United States Census.
• Stony Brook University, a major public research university, is located within the 631 area.
• Long Island MacArthur Airport in Ronkonkoma is within the 631 service area.
• Fire Island, the Hamptons, and Montauk are all within the broader region served by area code 631.

Frequently Asked Questions

What state is area code 631 in?

Area code 631 is in New York.

What major cities use area code 631?

Major communities that use area code 631 include Babylon, Huntington, Islip, Smithtown, Brookhaven, Riverhead, and Southampton.

Is area code 631 a toll-free number?

No, area code 631 is a geographic area code for Suffolk County, New York.