Phone numbers in Danbury, Connecticut
Danbury has 72 phone prefixes in area codes 203, 475.
Biggest holders: AT&T (local phone), Verizon Wireless, T-Mobile (including Sprint). This is the local calling area (rate center) where those prefixes were first assigned.
- Mobile carrier 44%
- Local phone company 35%
- Internet / business phone carrier 17%
- Paging service 1%
- Phone company 3%
Every prefix in Danbury
Search the first six digits of a number in this list. If it's here, the number started in Danbury with the carrier shown. If it isn't, check the Connecticut page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 203-205 | AT&T (local phone) | Local phone company | – |
| 203-207 | AT&T (local phone) | Local phone company | – |
| 203-240 | Verizon Wireless | Mobile carrier | – |
| 203-241 | Verizon Wireless | Mobile carrier | – |
| 203-289 | Spok | Paging service | – |
| 203-297 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 203-300 | T-Mobile (including Sprint) | Mobile carrier | 2001 |
| 203-312 | AT&T (local phone) | Local phone company | – |
| 203-313 | Verizon Wireless | Mobile carrier | – |
| 203-417 | AT&T Mobility | Mobile carrier | – |
| 203-448 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 203-456 | Verizon Wireless | Mobile carrier | 2011 |
| 203-460 | MetroPCS (T-Mobile) | Mobile carrier | – |
| 203-470 | Verizon Wireless | Mobile carrier | – |
| 203-482 | AT&T Mobility | Mobile carrier | 2001 |
| 203-501 | Verizon Wireless | Mobile carrier | 2010 |
| 203-512 | T-Mobile (including Sprint) | Mobile carrier | – |
| 203-546 | Teleport Communications America | Internet / business phone carrier | – |
| 203-616 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 203-617 | T-Mobile (including Sprint) | Mobile carrier | 2006 |
| 203-628 | Cablevision Lightpath | Internet / business phone carrier | – |
| 203-648 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 203-702 | Windstream (PAETEC) | Internet / business phone carrier | – |
| 203-730 | AT&T (local phone) | Local phone company | – |
| 203-731 | AT&T (local phone) | Local phone company | – |
| 203-733 | Verizon Wireless | Mobile carrier | – |
| 203-739 | AT&T (local phone) | Local phone company | – |
| 203-740 | AT&T (local phone) | Local phone company | – |
| 203-743 | AT&T (local phone) | Local phone company | – |
| 203-744 | AT&T (local phone) | Local phone company | – |
| 203-746 | AT&T (local phone) | Local phone company | – |
| 203-748 | AT&T (local phone) | Local phone company | – |
| 203-749 | AT&T (local phone) | Local phone company | – |
| 203-770 | AT&T Mobility | Mobile carrier | – |
| 203-775 | AT&T (local phone) | Local phone company | – |
| 203-778 | AT&T (local phone) | Local phone company | – |
| 203-788 | AT&T Mobility | Mobile carrier | – |
| 203-790 | AT&T (local phone) | Local phone company | – |
| 203-791 | AT&T (local phone) | Local phone company | – |
| 203-792 | AT&T (local phone) | Local phone company | – |
| 203-794 | AT&T (local phone) | Local phone company | – |
| 203-796 | AT&T (local phone) | Local phone company | – |
| 203-797 | AT&T (local phone) | Local phone company | – |
| 203-798 | AT&T (local phone) | Local phone company | – |
| 203-825 | AT&T (local phone) | Local phone company | – |
| 203-826 | AT&T (local phone) | Local phone company | – |
| 203-830 | AT&T (local phone) | Local phone company | – |
| 203-837 | AT&T (local phone) | Local phone company | – |
| 203-885 | Verizon Wireless | Mobile carrier | 2006 |
| 203-917 | Verizon Wireless | Mobile carrier | 2008 |
| 203-942 | T-Mobile (including Sprint) | Mobile carrier | – |
| 203-947 | AT&T Mobility | Mobile carrier | – |
| 203-948 | T-Mobile (including Sprint) | Mobile carrier | – |
| 203-994 | T-Mobile (including Sprint) | Mobile carrier | 2001 |
| 475-204 | Verizon Wireless | Mobile carrier | 2012 |
| 475-206 | T-Mobile (including Sprint) | Mobile carrier | 2015 |
| 475-218 | Verizon Wireless | Mobile carrier | 2015 |
| 475-237 | Verizon Wireless | Mobile carrier | 2017 |
| 475-256 | T-Mobile (including Sprint) | Mobile carrier | 2018 |
| 475-279 | Verizon Wireless | Mobile carrier | 2015 |
| 475-289 | Verizon Wireless | Mobile carrier | 2014 |
| 475-290 | Bandwidth | Internet / business phone carrier | 2021 |
| 475-296 | T-Mobile (including Sprint) | Mobile carrier | 2021 |
| 475-329 | Bandwidth | Internet / business phone carrier | 2014 |
| 475-348 | AT&T Mobility | Mobile carrier | 2020 |
| 475-370 | Boost / Virgin Mobile | Mobile carrier | 2024 |
| 475-380 | Eon Telecom | Phone company | 2024 |
| 475-454 | Onvoy | Internet / business phone carrier | 2020 |
| 475-529 | Verizon Wireless | Mobile carrier | 2011 |
| 475-678 | Teleport Communications America | Internet / business phone carrier | 2025 |
| 475-750 | Barr Tel USA | Phone company | 2022 |
| 475-867 | Commio | Internet / business phone carrier | 2022 |
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.