Phone numbers in Darien, Connecticut
Darien has 20 phone prefixes in area codes 203, 475.
Biggest holders: MCImetro (Verizon Business), AT&T (local phone), MetroPCS (T-Mobile). This is the local calling area (rate center) where those prefixes were first assigned.
- Mobile carrier 15%
- Local phone company 20%
- Internet / business phone carrier 65%
Every prefix in Darien
Search the first six digits of a number in this list. If it's here, the number started in Darien with the carrier shown. If it isn't, check the Connecticut page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 203-202 | Cablevision Lightpath | Internet / business phone carrier | – |
| 203-280 | MCImetro (Verizon Business) | Internet / business phone carrier | 2004 |
| 203-309 | MetroPCS (T-Mobile) | Mobile carrier | 2007 |
| 203-320 | MCImetro (Verizon Business) | Internet / business phone carrier | 2003 |
| 203-424 | MetroPCS (T-Mobile) | Mobile carrier | 2007 |
| 203-559 | Teleport Communications America | Internet / business phone carrier | – |
| 203-620 | MCImetro (Verizon Business) | Internet / business phone carrier | 2004 |
| 203-621 | Windstream (PAETEC) | Internet / business phone carrier | – |
| 203-636 | MCImetro (Verizon Business) | Internet / business phone carrier | 2004 |
| 203-655 | AT&T (local phone) | Local phone company | – |
| 203-656 | AT&T (local phone) | Local phone company | – |
| 203-662 | AT&T (local phone) | Local phone company | – |
| 203-669 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 203-875 | AT&T (local phone) | Local phone company | – |
| 203-898 | MCImetro (Verizon Business) | Internet / business phone carrier | 2005 |
| 475-259 | MetroPCS (T-Mobile) | Mobile carrier | 2017 |
| 475-264 | Onvoy | Internet / business phone carrier | – |
| 475-328 | MCImetro (Verizon Business) | Internet / business phone carrier | 2014 |
| 475-336 | Fractel | Internet / business phone carrier | 2020 |
| 475-368 | Onvoy | Internet / business phone carrier | 2024 |
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.