Phone numbers in Cedarburg, Wisconsin
Cedarburg has 14 phone prefixes in area code 262.
Biggest holders: AT&T (local phone), Onvoy, Level 3 (Lumen). This is the local calling area (rate center) where those prefixes were first assigned.
- Local phone company 36%
- Internet / business phone carrier 64%
Every prefix in Cedarburg
Search the first six digits of a number in this list. If it's here, the number started in Cedarburg with the carrier shown. If it isn't, check the Wisconsin page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 262-204 | Teleport Communications America, LLC Wi | Internet / business phone carrier | – |
| 262-228 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 262-274 | Onvoy | Internet / business phone carrier | 2021 |
| 262-304 | Onvoy | Internet / business phone carrier | 2021 |
| 262-329 | AT&T (local phone) | Local phone company | 2010 |
| 262-375 | AT&T (local phone) | Local phone company | – |
| 262-376 | AT&T (local phone) | Local phone company | – |
| 262-377 | AT&T (local phone) | Local phone company | – |
| 262-387 | AT&T (local phone) | Local phone company | – |
| 262-401 | Onvoy | Internet / business phone carrier | 2023 |
| 262-421 | Level 3 (Lumen) | Internet / business phone carrier | 2001 |
| 262-474 | Windstream (PAETEC) | Internet / business phone carrier | – |
| 262-546 | Windstream (PAETEC) | Internet / business phone carrier | – |
| 262-618 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
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.