631 area code: Suffolk County, Long Island

Updated: 10/16/2026

631 is the area code for Suffolk County, Long Island. Phone numbers with this area code are written as (631) XXX-XXXX.

631 area code - Suffolk County, Long Island

Area code631
AreaSuffolk County, Long Island
State or regionNew York
Time zoneEastern Time (ET)
Number format(631) XXX-XXXX
International format+1 631-XXX-XXXX

Overlay: the same area is also served by area code 934, so local calls need all 10 digits.

An area code does not prove where the caller is. People keep their number when they move or switch carriers, internet phone (VoIP) services hand out numbers in any area code, and scammers often fake a local area code (neighbor spoofing) to get you to pick up.

Missed call from a number starting with 631 - what to do

  • Look up the full number in the search below to see reviews and reports from other people.
  • Never read out one-time passcodes, card details or online banking passwords over the phone. No real bank, government agency or police department will ask you to move money to a "safe account" or pay with gift cards.
  • Forward spam texts to 7726 (SPAM) for free and report scams to the FTC at reportfraud.ftc.gov. Internet-based fraud can also be reported to the FBI at ic3.gov.

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