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

MASON CITY prefixes in area code 641

NANPA records 20 assigned NXX blocks to rate center MASON CITY in area code 641, 3.4% of the 584 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. 8 holders hold those blocks, the largest being QWEST CORPORATION (7), T-MOBILE USA, INC. (4), UNITED STATES CELLULAR - IA (3). The earliest assignment on record here is 2001-04-09 and the most recent 2024-03-12. 14 of them are in thousands-block pooling, so those prefixes are shared between carriers in 1,000-number lots. The same rate center name also appears in area codes 217, 308, 447 – overlay codes cover the same geography, so a rate center is served by all of them.

20 assigned blocks – 3.4% of 641
8 holders of record
14 of them pooled in 1,000-number lots

Prefixes assigned here

PrefixHolder of recordAssignedPooledIn service
641-201 T-Mobile METROPCS, INC. 2001-04-09 yes yes
641-210 T-Mobile T-MOBILE USA, INC. 2001-08-02 yes yes
641-243 Lumen LEVEL 3 COMMUNICATIONS, LLC - IA 2009-10-26 yes yes
641-255 T-Mobile T-MOBILE USA, INC. 2022-04-28 yes yes
641-380 Lumen QWEST CORPORATION – no yes
641-420 Verizon CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IA – no yes
641-421 Lumen QWEST CORPORATION – no yes
641-422 Lumen QWEST CORPORATION – no yes
641-423 Lumen QWEST CORPORATION – no yes
641-424 Lumen QWEST CORPORATION – no yes
641-425 UNITED STATES CELLULAR - IA – yes yes
641-428 Lumen QWEST CORPORATION 2010-08-18 yes yes
641-430 UNITED STATES CELLULAR - IA – yes yes
641-450 NORTHLAND COMMUNICATIONS, INC. - IA 2013-05-16 yes yes
641-494 Lumen QWEST CORPORATION – yes yes
641-512 UNITED STATES CELLULAR - IA – yes yes
641-513 Onvoy ONVOY, LLC - IA 2024-03-12 yes yes
641-530 Verizon CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IA – yes yes
641-548 T-Mobile T-MOBILE USA, INC. 2018-03-06 yes yes
641-903 T-Mobile T-MOBILE USA, INC. 2005-06-17 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
QWEST CORPORATION Lumen 7 35%
T-MOBILE USA, INC. T-Mobile 4 20%
UNITED STATES CELLULAR - IA – 3 15%
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IA Verizon 2 10%
METROPCS, INC. T-Mobile 1 5%
LEVEL 3 COMMUNICATIONS, LLC - IA Lumen 1 5%
NORTHLAND COMMUNICATIONS, INC. - IA – 1 5%
ONVOY, LLC - IA Onvoy 1 5%

Frequently asked

Which prefixes belong to MASON CITY in area code 641?

20 blocks: 201, 210, 243, 255, 380, 420, 421, 422, 423, 424, 425, 428 and 8 more, all listed in the table above.

Which carriers have numbers in MASON CITY?

QWEST CORPORATION (7 blocks), T-MOBILE USA, INC. (4 blocks), UNITED STATES CELLULAR - IA (3 blocks), CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IA (2 blocks), METROPCS, INC. (1 block), LEVEL 3 COMMUNICATIONS, LLC - IA (1 block). These are the holders on record; the carrier actually serving a given number can differ, because numbers move with their owners.

Is MASON CITY 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 641

All 584 prefixes in 641