Area code
631
631 is a United States area code. Under the North American Numbering Plan it belongs to New York, which has 23 area codes in total.
Validate a number in 631
Paste a full number and the tool checks it against the numbering plan. It returns the standard formats, the line type the plan assigns and the area code region.
Digits with or without punctuation work. Numbers outside the US are read with the +country code.
Area code 631 at a glance
NANPA lists 782 central office codes (prefixes) in use in area code 631, held by 38 holders across 54 rate centers.
| Fact | Value |
|---|---|
| In service since | 1999-11-01 |
| Time zone | Eastern (E) |
| Assigned overlays | 934 (2016-07-16) |
| Prefixes in use | 782 |
| Pooled prefixes | 600 (77%) |
| Rate centers | 54 |
| Companies holding prefixes | 38 |
| Assignment dates on file | 2001-01-16 to 2025-09-03 (285 prefixes) |
| ZIP codes in its places | 34 |
Rate centers in area code 631
| Rate center | Prefixes | Share |
|---|---|---|
| BRENTWOOD | 127 | 16% |
| FARMINGDL | 42 | 5% |
| RIVERHEAD | 40 | 5% |
| HUNTINGTON | 34 | 4% |
| CENTRAISLP | 32 | 4% |
| AMITYVILLE | 31 | 4% |
| BABYLON | 28 | 4% |
| DEER PARK | 27 | 3% |
| 46 other rate centers | 421 | 54% |
Who holds the prefixes in 631
Verizon New York holds the most prefixes, 228 (29%). 77% of the prefixes are pooled, which means their thousands-blocks can belong to different companies.
| Holder | Prefixes | Share |
|---|---|---|
| Verizon New York | 228 | 29% |
| Mcimetro Access Transmission Services | 65 | 8% |
| Cablevision Lightpath | 55 | 7% |
| Omnipoint Communications | 55 | 7% |
| Level 3 Communications | 53 | 7% |
| New Cingular Wireless PCS | 49 | 6% |
| 32 other carriers | 277 | 35% |
A prefix holder is the company a code was assigned to, not necessarily a number's current carrier, because numbers can be ported to another company. Find which carrier a number is on, or browse the prefix holders.
History of area code 631
- 1951-01-01 Area code 516, named as the parent of 631 in the NANPA report, was in service.
- 1999-11-01 Area code 631 went into service.
- 2016-07-16 Area code 934 went into service as an overlay in the same area as 631.
Area codes nearest to 631
Distance is measured between the centers of the ZIP code places each area code serves, so it is a rough guide.
Overlay codes in the same area
ZIP codes in area code 631
34 ZIP codes fall in places that have a rate center in this area code.
| Place | ZIP codes |
|---|---|
| Stony Brook, NY | 2 |
| Amagansett, NY | 1 |
| Amityville, NY | 1 |
A ZIP code and an area code are unrelated systems. A ZIP code can sit in more than one area code, and an area code spans many ZIP codes.
Complaints on file for 631 numbers
4,834 FCC complaints are on file for 3,262 numbers in 631, most often filed as "Unwanted Calls". These are unverified consumer reports.
| Year of latest complaint | Numbers |
|---|---|
| 2023 | 128 |
| 2024 | 101 |
| 2025 | 213 |
Other area codes in New York
New York is one state with 23 area codes in the NANPA table. 631 is one of them.
Next to 631 in the numbering table
These are the codes just before and after 631 when all are sorted by number. They are neighbours on the list, not necessarily on the map.
What the area code does and does not tell you
A number that starts with 631 was first assigned in New York. That is a fact about where the number began, and it is a useful hint when you check a form entry, for example a billing address in New York next to a 631 phone number.
It does not show where the person is today. A number stays with its owner after a move or a change of provider (number portability), and mobile numbers travel with the handset. The area code also cannot tell you whether the line is active, who the carrier is, or whether the number is mobile or fixed: the plan shares those ranges. Read more about the area code, the numbering plan and line type.
Check numbers in bulk with the API
| Product | Credits | Docs |
|---|---|---|
| Phone Numbering-Plan Validation | 1 credit per valid number | API docs |
| Phone Intelligence (carrier and line status) | 1 credit per check (invalid numbers outside the US and Canada are free) | Product page |
Questions about area code 631
Where is area code 631?
NANPA assigns area code 631 to New York, United States.
In which state does area code 631 sit?
New York. 631 is one of 23 area codes the NANPA table assigns to the state.
Which places does area code 631 cover?
The places with the most ZIP codes among the rate centers in 631 are Stony Brook, NY, Amagansett, NY and Amityville, NY. The rate center list on this page shows all of them.
Who owns area code 631?
NANPA assigns area codes. Within 631, Verizon New York holds the most prefixes, 228 prefixes or 29%.
Which time zone does 631 use?
The NANPA NPA report lists the time zone for 631 as Eastern (E).
What year did 631 enter service?
The NANPA NPA report gives an in-service date of 1999-11-01, so 631 has been in use since 1999.
Does area code 631 have an overlay?
Yes. 934 (in service 2016-07-16) shares the same area with 631, so numbers from all of them are local to each other.
Which area codes are nearest to 631?
The area codes closest to 631, measured between the centers of the ZIP code places they serve, are 516 (about 18 miles), 203 (about 32 miles), 475 (about 32 miles), 551 (about 60 miles) and 860 (about 60 miles).
How many prefixes does area code 631 have?
NANPA's report dated 2026-10-17 lists 782 prefixes in service in 631, spread over 54 rate centers and 38 holders.
Are there complaints about 631 numbers?
The FCC data on file has 4,834 complaints for 3,262 numbers in 631. They are unverified consumer reports. A number with no complaints on file is not proven safe.
Area code assignments: North American Numbering Plan Administrator NPA report, file dated 10/17/2026, retrieved 2026-10-17. Source file. New codes are assigned several times a year. Prefixes, rate centers, holders, time zone, in-service date and overlays: NANPA central office code report dated 2026-10-17 and NPA report dated 2026-10-18. Complaints: FCC consumer complaints open data, fetched 2026-10-17. ZIP code places: Postal code places and coordinates: GeoNames (geonames.org), licensed CC BY 4.0.