Phone numbers in Islip, New York
Islip has 13 phone prefixes in area codes 631, 934.
Biggest holders: Verizon (local phone), Cablevision Lightpath, Windstream (PAETEC). This is the local calling area (rate center) where those prefixes were first assigned.
- Local phone company 31%
- Internet / business phone carrier 62%
- Phone company 8%
Every prefix in Islip
Search the first six digits of a number in this list. If it's here, the number started in Islip with the carrier shown. If it isn't, check the New York page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 631-210 | Windstream (PAETEC) | Internet / business phone carrier | – |
| 631-224 | Verizon (local phone) | Local phone company | – |
| 631-277 | Verizon (local phone) | Local phone company | – |
| 631-313 | Cablevision Lightpath | Internet / business phone carrier | 2018 |
| 631-446 | Csc Voice | Internet / business phone carrier | 2007 |
| 631-481 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 631-581 | Verizon (local phone) | Local phone company | – |
| 631-650 | Cablevision Lightpath | Internet / business phone carrier | – |
| 631-840 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 631-859 | Verizon (local phone) | Local phone company | – |
| 631-960 | Tc Systems | Phone company | – |
| 934-250 | Commio | Internet / business phone carrier | 2023 |
| 934-758 | Fractel | Internet / business phone carrier | 2021 |
Most prefixes are pooled: the 10,000 numbers in each are handed out in blocks of 1,000 to different carriers, and people can also take their numbers to another carrier. So the carrier shown is where the prefix started, not a guarantee about any one number. Source: NANPA central office code records, 2026-10-10.