phonenumbers
New York Area Codes
LOGIN
LOGIN

Where Is 631 Area Code?

Search For a Phone Number
To look up the owner
SEARCH
Results include when available
Owner's Name
Owner’s Email Addresses
Relatives & Associates
Location(s)
Social Profiles
Images & Videos
Social Profiles
Images & Videos
Database Updated: July 23, 2025
New York Phone Number Lookups
Where Is 631 Area Code?

Where is Area Code 631?

Area Code 631 covers the eastern portion of Long Island in New York State. It primarily serves the residents and businesses within Suffolk County, as well as parts of Fire Island. Major towns and municipalities in this region include:

  • Huntington
  • Smithtown
  • Brookhaven
  • Islip
  • Riverhead
  • Southold

Each of these locations has local government offices committed to providing public services and resources. Citizens who require further guidance on administrative matters related to Area Code 631 may refer to the county’s official website for official Suffolk County resources. To visit the county offices in person, consult the Suffolk County Executive’s office, located at 300 Center Drive, Riverhead, NY 11901.

What time zone is 631 area code in the USA?

The 631 area code observes the Eastern Time Zone (ET) in the United States. This time zone is regulated according to US time zone information, including observance of Daylight Saving Time (DST). Residents and businesses typically shift their clocks one hour forward in the spring and return to standard time in the fall, following guidelines established under federal and state regulations.

History of the 631 Area Code

Area Code 631 was introduced in 1999 as a result of a geographic split from the 516 area code. Rapid population growth and increased demand for telephone numbers led to the creation of the new code:

  • Year of Creation: 1999
  • Origin: Split from Area Code 516
  • Reasons for Change: Growing population, increased use of mobile devices, and an expansion of fax and internet services

In expectation of further demand, the region adopted an overlay plan in 2016, nurturing the introduction of Area Code 934 to supplement 631. According to NANPA resources, the overlay plan ensures an adequate supply of telephone numbers for residents and businesses without forcing existing telephone lines to change their area codes again.

How Many People Use the 631 Area Code?

Area Code 631 supports a broad segment of Suffolk County’s population. Suffolk County is home to approximately 1.5 million residents, many of whom use the 631 area code for their landlines and mobile devices. Additionally, thousands of businesses within this region also maintain phone lines under this code for local, national, and international communications. For further insight into population statistics or to submit inquiries related to demographics, individuals can consult NY official government information or contact the New York State Department of Labor for employment data. The Department of Labor’s main office can be found at Building 12, W.A. Harriman Campus, Albany, NY 12240.

Is the 631 Area Code Toll-Free?

Area Code 631 is not a toll-free telephone code; it is strictly associated with a geographic region. Calls placed within most parts of Suffolk County are often considered local, but calls outside the coverage area or long-distance calls follow standard billing practices set by various telephone service providers. Consumer protection guidelines are outlined by the FCC guidelines, and any individual with concerns may file a complaint through official channels. The Federal Communications Commission can be contacted at 445 12th Street SW, Washington, DC 20554 for queries related to local and national calling regulations.

Cities in 631 Area Code
  • Brentwood
  • West Babylon
  • Coram
  • Commack
  • Central Islip
  • Huntington Station
  • Centereach
  • West Islip
  • Shirley
  • Deer Park
  • Lindenhurst
  • Holbrook
  • Dix Hills
  • Smithtown
  • Bay Shore
  • Medford
  • Copiague
  • East Patchogue
  • Hauppauge
  • East Northport
  • Lake Ronkonkoma
  • Selden
  • Holtsville
  • Ronkonkoma
  • North Bay Shore
  • Islip
  • Huntington
  • North Amityville
  • North Babylon
  • Kings Park
  • Sayville
  • Melville
  • Farmingville
  • Mastic
  • Setauket-East Setauket
  • East Islip
  • Manorville
  • Rocky Point
  • Greenlawn
  • Stony Brook
  • Hampton Bays
  • Nesconset
  • St. James
  • Ridge
  • Riverhead
  • Mastic Beach
  • Miller Place
  • Babylon
  • Mount Sinai
  • Terryville
Counties in 631 Area Code
  • Suffolk
Prefix Codes for Area Code 631
  • (631) 200
  • (631) 204
  • (631) 205
  • (631) 206
  • (631) 207
  • (631) 208
  • (631) 209
  • (631) 210
  • (631) 213
  • (631) 216
  • (631) 217
  • (631) 218
  • (631) 219
  • (631) 220
  • (631) 221
  • (631) 223
  • (631) 224
  • (631) 225
  • (631) 226
  • (631) 227
  • (631) 228
  • (631) 229
  • (631) 230
  • (631) 231
  • (631) 232
  • (631) 233
  • (631) 234
  • (631) 235
  • (631) 236
  • (631) 237
  • (631) 238
  • (631) 239
  • (631) 240
  • (631) 241
  • (631) 242
  • (631) 243
  • (631) 244
  • (631) 245
  • (631) 246
  • (631) 247
New York Area Codes
  • 212
  • 315
  • 329
  • 332
  • 347
  • 363
  • 516
  • 518
  • 585
  • 607
  • 624
  • 631
  • 646
  • 680
  • 716
  • 718
  • 838
  • 845
  • 914
  • 917
  • 929
  • 934
New York Phone Numbers
HomeFAQPrivacyTerms of UseYour Privacy ChoicesAccessibility Statement
Do Not Sell / Share My Personal Information