Area codes · +1
Area code 631
Area code 631 is centred on Brentwood, New York. We hold 6,547 allocated blocks for it across 54 rate centres, split 33% mobile, 57% landline and 10% VoIP.
The other area codes laid over 631
Area code 631 does not have Brentwood to itself. 1 other code — 934 — serves the same rate centres, laid over the same ground rather than dividing it. That is an overlay: a new code added when the old one ran out of numbers, covering the same streets. Two neighbours can hold different area codes, so the code says roughly when a number was issued rather than where it sits.
9341,283 blocks, 46 rate centres, mostly mobile
Each holds its own blocks and its own carrier mix, so a 631 number and a 934 number from the same street can report different line types. Filtering Brentwood by area code needs all 2 of them.
631 is not confined to Brentwood itself: its blocks sit across 54 rate centres, named in the table below.
New York is split across 21 area codes — 347, 929, 646, 845, 315, 631 and others. By allocated blocks 631 is the 7th largest of them, holding 7% of the New York total.
Where 631 numbers are concentrated
NANPA truncates rate-centre names to ten characters and drops the spaces, which is why W Commack is shortened. Names are reproduced as recorded rather than expanded — the abbreviation is the key the block data is filed under.
| Rate centre | Blocks | Share of 631 |
|---|---|---|
| Brentwood | 1,027 | 16% |
| Riverhead | 340 | 5% |
| Farmingdl | 312 | 5% |
| Amityville | 307 | 5% |
| Centraislp | 269 | 4% |
| Patchogue | 236 | 4% |
| Huntington | 230 | 4% |
| Babylon | 228 | 3% |
| Deer Park | 227 | 3% |
| Selden | 192 | 3% |
| Yaphank | 167 | 3% |
| Ronkonkoma | 166 | 3% |
| Smithtown | 159 | 2% |
| Lindenhst | 132 | 2% |
| Bay Shore | 123 | 2% |
| Ptjeffersn | 114 | 2% |
| W Commack | 113 | 2% |
| Stonybrook | 112 | 2% |
| Southamptn | 102 | 2% |
| Sayville | 94 | 1% |
| Islip | 91 | 1% |
| Commack | 90 | 1% |
| Northport | 89 | 1% |
| Bayport | 87 | 1% |
30 further rate centres in 631 hold fewer blocks than these.
Carriers holding the most 631 blocks
Verizon New York, Inc.661 blocks
Onvoy624 blocks
Verizon Wireless491 blocks
T-Mobile USA, Inc.466 blocks
AT&T Wireless456 blocks
Omnipoint Communications, Inc.303 blocks
No carrier holds more than 10% of 631; the blocks are spread thin across many companies.
These are original allocations. A number keeps its digits and its block when its subscriber moves network, so a ported 631 number still reports the carrier it started with. Closing that gap needs a live query against the routing database. How line type is derived.
Check a single 631 number, or run a whole list through the free cleaner — neither uploads anything.
Common questions
Where is area code 631?
Area code 631 covers Brentwood, New York. It is not the only code there: 934 is an overlay on the same rate centres, so a Brentwood, New York number can start with any of them.
Is a 631 number a mobile or a landline?
It can be either, and the digits do not say which. North American mobile and landline numbers share the same ranges, so the answer comes from the carrier holding the block. In 631 the split runs 33% mobile, 57% landline and 10% VoIP, so landline is the most likely single answer.
Which carriers hold 631 numbers?
The largest holders are Verizon New York, Inc., Onvoy, Verizon Wireless. That is the carrier the block was allocated to, which is not necessarily the network a given number sits on today.
How many 631 numbers are there?
The code holds 6,547 allocated blocks in our copy of the numbering plan. A block is 1,000 or 10,000 consecutive numbers depending on how deeply it has been pooled, so 631 covers on the order of 6,547,000 possible numbers — most of which have never been issued to anyone.