Area Code 631
New York
Geographic Coverage
State
NY
Major Cities
- West Babylon
- Coram
- Central Islip
- Commack
- Huntington Station
- Centereach
- Bay Shore
- Shirley
- Deer Park
- Lindenhurst
- West Islip
- Holbrook
- Medford
- Dix Hills
- Smithtown
- Copiague
- Selden
- East Patchogue
- Hauppauge
- North Bay Shore
- North Amityville
- Huntington
- East Northport
- Holtsville
and 135 more cities
Time Zone
- Eastern Time (ET)
Current Time
Demographics & Economics
- Total Population
- 1,465,782
- Population Density
- 1,700 people/sq miabove U.S. average (U.S.: 94 people/sq mi)
- Median Household Income
- $128,329above U.S. median (U.S.: $78,538)
- Poverty Rate
- 6.4%below U.S. average (U.S.: 12.4%)
- Unemployment Rate
- 4.6%below U.S. average (U.S.: 5.2%)
- Education Attainment
- Bachelor's Degree+40.1%above U.S. average (U.S.: 35.0%)High School or Lower29.9%
Statistics are population-weighted aggregations from Census ACS 5-year estimates.See Sources for details.
Overlay Area Code
This area code is part of an overlay region, meaning the same geographic area is served by multiple area codes. Overlay codes were introduced to meet growing demand for phone numbers without requiring existing customers to change their numbers.
This area code shares its geographic region with: area code 934.
In service since: 01-Nov-1999
Call Context
This area code covers multiple cities and communities across a broad region in New York.
County Coverage
Population-weighted county share based on aggregated ZCTA population (100% = total mapped population for area code 631).
| County | Population | Share |
|---|---|---|
| Suffolk, NY | 1,433,004 | 97.8% |
| Nassau, NY | 32,778 | 2.2% |
Nearby Area Codes
Area codes geographically closest to 631.
Frequently Asked Questions
Common questions about area code 631 and how phone numbering works.
Phone numbers are assigned based on where the number was originally provisioned, not the caller's current location. Mobile phones retain their number when users move, and businesses may use numbers from regions where they don't have a physical presence. VoIP services can also provision numbers from virtually any area code.
Yes, mobile phones can have numbers from any area code in the region they were activated. Wireless carriers assign numbers from available pools regardless of phone type. When users change carriers or move to new areas, they typically keep their original number, which may have a different area code than their current location.
Start by looking up the area code on this site to understand its general geographic region. For the specific number, options include using your carrier's caller ID features or checking public directories. If you suspect fraud, you can report it to the FTC. To file a complaint about robocalls or spoofed numbers, visit the FCC Consumer Complaint Center. You can also register your number with the National Do Not Call Registry to reduce unwanted calls. Keep in mind that caller ID can display any name the caller chooses to set.
When an area's pool of available phone numbers runs low, regulators may introduce an "overlay" area code that covers the same geographic territory as the original. Both codes coexist, and new numbers are assigned from whichever code has availability. Learn more in our overlay vs split guide.
While New York is a prominent city in this area code's coverage, the code serves the broader surrounding region as well. Area codes are assigned geographically and typically cover multiple cities, towns, and communities beyond any single anchor city.
This area code covers a metropolitan region with high population density. Dense urban areas typically have higher call volumes and may have multiple overlapping area codes to meet demand for phone numbers. Businesses and residents in these areas are more likely to need additional numbering resources.