Phone numbers in Stamford, Connecticut
Stamford has 124 phone prefixes in area codes 203, 475.
Biggest holders: AT&T (local phone), Verizon Wireless, AT&T Mobility. This is the local calling area (rate center) where those prefixes were first assigned.
- Mobile carrier 27%
- Local phone company 41%
- Internet / business phone carrier 31%
- Paging service 1%
- Phone company 1%
Every prefix in Stamford
Search the first six digits of a number in this list. If it's here, the number started in Stamford with the carrier shown. If it isn't, check the Connecticut page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 203-219 | AT&T Mobility | Mobile carrier | – |
| 203-223 | T-Mobile (including Sprint) | Mobile carrier | – |
| 203-249 | Verizon Wireless | Mobile carrier | – |
| 203-251 | AT&T (local phone) | Local phone company | – |
| 203-252 | Cablevision Lightpath | Internet / business phone carrier | – |
| 203-253 | Verizon Wireless | Mobile carrier | – |
| 203-273 | Verizon Wireless | Mobile carrier | 2002 |
| 203-274 | AT&T Mobility | Mobile carrier | – |
| 203-276 | Cablevision Lightpath | Internet / business phone carrier | 2003 |
| 203-282 | Spok | Paging service | – |
| 203-316 | AT&T (local phone) | Local phone company | – |
| 203-321 | AT&T (local phone) | Local phone company | – |
| 203-322 | AT&T (local phone) | Local phone company | – |
| 203-323 | AT&T (local phone) | Local phone company | – |
| 203-324 | AT&T (local phone) | Local phone company | – |
| 203-325 | AT&T (local phone) | Local phone company | – |
| 203-326 | AT&T (local phone) | Local phone company | – |
| 203-327 | AT&T (local phone) | Local phone company | – |
| 203-328 | AT&T (local phone) | Local phone company | – |
| 203-329 | AT&T (local phone) | Local phone company | – |
| 203-348 | AT&T (local phone) | Local phone company | – |
| 203-351 | AT&T (local phone) | Local phone company | – |
| 203-352 | AT&T (local phone) | Local phone company | – |
| 203-353 | AT&T (local phone) | Local phone company | – |
| 203-355 | Cablevision Lightpath | Internet / business phone carrier | – |
| 203-356 | AT&T (local phone) | Local phone company | – |
| 203-357 | AT&T (local phone) | Local phone company | – |
| 203-358 | AT&T (local phone) | Local phone company | – |
| 203-359 | AT&T (local phone) | Local phone company | – |
| 203-363 | AT&T (local phone) | Local phone company | – |
| 203-388 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 203-391 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 203-399 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 203-406 | AT&T (local phone) | Local phone company | – |
| 203-425 | AT&T (local phone) | Local phone company | – |
| 203-428 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 203-461 | AT&T (local phone) | Local phone company | – |
| 203-462 | AT&T (local phone) | Local phone company | – |
| 203-487 | Level 3 (Lumen) | Internet / business phone carrier | 2001 |
| 203-504 | Windstream (PAETEC) | Internet / business phone carrier | 2004 |
| 203-517 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 203-524 | AT&T Mobility | Mobile carrier | – |
| 203-536 | Verizon Wireless | Mobile carrier | – |
| 203-539 | AT&T (local phone) | Local phone company | – |
| 203-541 | AT&T (local phone) | Local phone company | – |
| 203-547 | Onvoy | Internet / business phone carrier | – |
| 203-548 | Level 3 (Lumen) | Internet / business phone carrier | 2002 |
| 203-550 | T-Mobile (including Sprint) | Mobile carrier | – |
| 203-554 | AT&T Mobility | Mobile carrier | – |
| 203-561 | Verizon Wireless | Mobile carrier | – |
| 203-564 | AT&T (local phone) | Local phone company | – |
| 203-566 | MCImetro (Verizon Business) | Internet / business phone carrier | 2003 |
| 203-569 | Cablevision Lightpath | Internet / business phone carrier | – |
| 203-570 | T-Mobile (including Sprint) | Mobile carrier | 2001 |
| 203-585 | AT&T (local phone) | Local phone company | – |
| 203-588 | Cablevision Lightpath | Internet / business phone carrier | – |
| 203-595 | AT&T (local phone) | Local phone company | – |
| 203-602 | AT&T (local phone) | Local phone company | – |
| 203-607 | MCImetro (Verizon Business) | Internet / business phone carrier | 2003 |
| 203-609 | AT&T (local phone) | Local phone company | – |
| 203-614 | AT&T (local phone) | Local phone company | – |
| 203-653 | Windstream (PAETEC) | Internet / business phone carrier | – |
| 203-658 | Teleport Communications America | Internet / business phone carrier | – |
| 203-667 | T-Mobile (including Sprint) | Mobile carrier | – |
| 203-674 | AT&T (local phone) | Local phone company | – |
| 203-703 | AT&T (local phone) | Local phone company | – |
| 203-705 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 203-708 | AT&T (local phone) | Local phone company | – |
| 203-719 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 203-724 | Windstream (PAETEC) | Internet / business phone carrier | – |
| 203-728 | AT&T (local phone) | Local phone company | 2006 |
| 203-817 | Cablevision Lightpath | Internet / business phone carrier | – |
| 203-832 | AT&T Mobility | Mobile carrier | 2006 |
| 203-883 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 203-890 | AT&T (local phone) | Local phone company | 2001 |
| 203-897 | MCImetro (Verizon Business) | Internet / business phone carrier | 2008 |
| 203-905 | Teleport Communications America | Internet / business phone carrier | – |
| 203-912 | Verizon Wireless | Mobile carrier | – |
| 203-914 | Csc Voice | Internet / business phone carrier | 2012 |
| 203-918 | AT&T Mobility | Mobile carrier | – |
| 203-921 | AT&T (local phone) | Local phone company | – |
| 203-940 | AT&T (local phone) | Local phone company | – |
| 203-960 | Cablevision Lightpath | Internet / business phone carrier | 2008 |
| 203-961 | AT&T (local phone) | Local phone company | – |
| 203-962 | AT&T (local phone) | Local phone company | – |
| 203-964 | AT&T (local phone) | Local phone company | – |
| 203-965 | AT&T (local phone) | Local phone company | – |
| 203-967 | AT&T (local phone) | Local phone company | – |
| 203-968 | AT&T (local phone) | Local phone company | – |
| 203-969 | AT&T (local phone) | Local phone company | – |
| 203-973 | AT&T (local phone) | Local phone company | – |
| 203-975 | AT&T (local phone) | Local phone company | – |
| 203-977 | AT&T (local phone) | Local phone company | – |
| 203-978 | AT&T (local phone) | Local phone company | – |
| 203-979 | AT&T Mobility | Mobile carrier | – |
| 203-989 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 203-998 | Level 3 (Lumen) | Internet / business phone carrier | 2004 |
| 475-205 | CenturyLink / Lumen | Local phone company | 2012 |
| 475-213 | Verizon Wireless | Mobile carrier | 2015 |
| 475-214 | Verizon Wireless | Mobile carrier | 2016 |
| 475-217 | Verizon Wireless | Mobile carrier | 2016 |
| 475-226 | Verizon Wireless | Mobile carrier | 2015 |
| 475-229 | Verizon Wireless | Mobile carrier | 2016 |
| 475-232 | Level 3 (Lumen) | Internet / business phone carrier | 2016 |
| 475-268 | T-Mobile (including Sprint) | Mobile carrier | 2020 |
| 475-276 | T-Mobile (including Sprint) | Mobile carrier | 2021 |
| 475-292 | AT&T Mobility | Mobile carrier | 2015 |
| 475-299 | Verizon Wireless | Mobile carrier | 2015 |
| 475-333 | Telnyx | Internet / business phone carrier | 2017 |
| 475-334 | Onvoy | Internet / business phone carrier | 2023 |
| 475-346 | Onvoy | Internet / business phone carrier | 2023 |
| 475-350 | Verizon Wireless | Mobile carrier | 2015 |
| 475-359 | Verizon Wireless | Mobile carrier | 2017 |
| 475-385 | AT&T Mobility | Mobile carrier | 2025 |
| 475-388 | AT&T Mobility | Mobile carrier | 2025 |
| 475-399 | Verizon Wireless | Mobile carrier | 2015 |
| 475-400 | Onvoy | Internet / business phone carrier | 2017 |
| 475-419 | Verizon Wireless | Mobile carrier | 2015 |
| 475-477 | Onvoy | Internet / business phone carrier | 2019 |
| 475-550 | Barr Tel USA | Phone company | 2022 |
| 475-619 | Teleport Communications America | Internet / business phone carrier | 2014 |
| 475-685 | Verizon Wireless | Mobile carrier | 2018 |
| 475-746 | TON80 Communications | Internet / business phone carrier | 2022 |
| 475-977 | Fractel | Internet / business phone carrier | 2020 |
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.