Phone numbers in Corte Madera, California
Corte Madera has 20 phone prefixes in area codes 415, 628.
Biggest holders: Onvoy, Bandwidth, AT&T (local phone). This is the local calling area (rate center) where those prefixes were first assigned.
- Mobile carrier 15%
- Local phone company 15%
- Internet / business phone carrier 70%
Every prefix in Corte Madera
Search the first six digits of a number in this list. If it's here, the number started in Corte Madera with the carrier shown. If it isn't, check the California page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 415-329 | Onvoy | Internet / business phone carrier | – |
| 415-413 | Teleport Communications America | Internet / business phone carrier | – |
| 415-496 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 415-548 | Onvoy | Internet / business phone carrier | 2002 |
| 415-737 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 415-758 | Tpx Communications | Internet / business phone carrier | – |
| 415-849 | Bandwidth | Internet / business phone carrier | 2014 |
| 415-886 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 415-891 | Comcast | Internet / business phone carrier | – |
| 415-924 | AT&T (local phone) | Local phone company | – |
| 415-927 | AT&T (local phone) | Local phone company | – |
| 415-936 | AT&T Mobility | Mobile carrier | 2014 |
| 415-945 | AT&T (local phone) | Local phone company | – |
| 628-212 | Bandwidth | Internet / business phone carrier | 2016 |
| 628-252 | T-Mobile (including Sprint) | Mobile carrier | 2016 |
| 628-266 | Bandwidth | Internet / business phone carrier | 2019 |
| 628-302 | T-Mobile (including Sprint) | Mobile carrier | 2024 |
| 628-386 | Fractel | Internet / business phone carrier | 2022 |
| 628-842 | Fractel | Internet / business phone carrier | 2020 |
| 628-877 | Onvoy | Internet / business phone carrier | 2016 |
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.