NumberingData
Verified Nov 1, 2026 · Source: NANPA CO Code Assignment Records

CEDARBURG prefixes in area code 262

NANPA records 14 assigned NXX blocks to rate center CEDARBURG in area code 262, 2.2% of the 634 blocks assigned in the code. A rate center is the billing geography a block is allocated to – NANPA truncates the name to ten characters, so read it as a NANPA label rather than a town. 6 holders hold those blocks, the largest being WISCONSIN BELL INC (5), ONVOY, LLC - WI (3), LEVEL 3 COMMUNICATIONS, LLC - WI (2). The earliest assignment on record here is 2001-12-10 and the most recent 2023-09-13. 11 of them are in thousands-block pooling, so those prefixes are shared between carriers in 1,000-number lots.

14 assigned blocks – 2.2% of 262
6 holders of record
11 of them pooled in 1,000-number lots

Prefixes assigned here

PrefixHolder of recordAssignedPooledIn service
262-204 AT&T TELEPORT COMMUNICATIONS AMERICA, LLC WI – yes yes
262-228 Lumen LEVEL 3 COMMUNICATIONS, LLC - WI – yes yes
262-274 Onvoy ONVOY, LLC - WI 2021-06-24 yes yes
262-304 Onvoy ONVOY, LLC - WI 2021-11-18 yes yes
262-329 AT&T WISCONSIN BELL INC 2010-02-01 yes yes
262-375 AT&T WISCONSIN BELL INC – no yes
262-376 AT&T WISCONSIN BELL INC – no yes
262-377 AT&T WISCONSIN BELL INC – no yes
262-387 AT&T WISCONSIN BELL INC – yes yes
262-401 Onvoy ONVOY, LLC - WI 2023-09-13 yes yes
262-421 Lumen LEVEL 3 COMMUNICATIONS, LLC - WI 2001-12-10 yes yes
262-474 Windstream PAETEC ITEL, LLC – yes yes
262-546 Windstream PAETEC ITEL, LLC – yes yes
262-618 Verizon MCIMETRO ACCESS TRANSMISSION SERVICES LLC – yes yes

The holder is who received the block from the numbering administrator. It is not necessarily the carrier serving a given number: numbers move with their owners, and a pooled block is shared.

Who holds the blocks

HolderBrandBlocksShare here
WISCONSIN BELL INC AT&T 5 35.7%
ONVOY, LLC - WI Onvoy 3 21.4%
LEVEL 3 COMMUNICATIONS, LLC - WI Lumen 2 14.3%
PAETEC ITEL, LLC Windstream 2 14.3%
TELEPORT COMMUNICATIONS AMERICA, LLC WI AT&T 1 7.1%
MCIMETRO ACCESS TRANSMISSION SERVICES LLC Verizon 1 7.1%

Frequently asked

Which prefixes belong to CEDARBURG in area code 262?

14 blocks: 204, 228, 274, 304, 329, 375, 376, 377, 387, 401, 421, 474 and 2 more, all listed in the table above.

Which carriers have numbers in CEDARBURG?

WISCONSIN BELL INC (5 blocks), ONVOY, LLC - WI (3 blocks), LEVEL 3 COMMUNICATIONS, LLC - WI (2 blocks), PAETEC ITEL, LLC (2 blocks), TELEPORT COMMUNICATIONS AMERICA, LLC WI (1 block), MCIMETRO ACCESS TRANSMISSION SERVICES LLC (1 block). These are the holders on record; the carrier actually serving a given number can differ, because numbers move with their owners.

Is CEDARBURG a city?

It is a rate center – the unit NANPA allocates number blocks to. Its name is abbreviated to ten characters and is not necessarily a settlement: we print it as recorded rather than guess at the full name.

Other rate centers in 262

All 634 prefixes in 262