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

COLUMBIA prefixes in area code 443

NANPA records 31 assigned NXX blocks to rate center COLUMBIA in area code 443, 3.9% of the 785 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. 12 holders hold those blocks, the largest being PAETEC ITEL, LLC (7), VERIZON MARYLAND, INC. (6), CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD (5). The earliest assignment on record here is 2001-01-15 and the most recent 2018-11-19. 28 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 207, 223, 235, 252 – overlay codes cover the same geography, so a rate center is served by all of them.

31 assigned blocks – 3.9% of 443
12 holders of record
28 of them pooled in 1,000-number lots

Prefixes assigned here

PrefixHolder of recordAssignedPooledIn service
443-259 Verizon VERIZON MARYLAND, INC. – yes yes
443-276 Verizon MCIMETRO ACCESS TRANSMISSION SERVICES LLC – yes yes
443-283 Windstream PAETEC ITEL, LLC – no yes
443-285 Verizon VERIZON MARYLAND, INC. – yes yes
443-319 Windstream PAETEC ITEL, LLC – yes yes
443-367 Verizon VERIZON MARYLAND, INC. – yes yes
443-393 Lumen LEVEL 3 COMMUNICATIONS, LLC - MD – yes yes
443-430 Verizon MCIMETRO ACCESS TRANSMISSION SERVICES LLC 2001-05-18 yes yes
443-472 Lumen LEVEL 3 COMMUNICATIONS, LLC - MD – yes yes
443-518 Verizon VERIZON MARYLAND, INC. 2008-12-16 yes yes
443-535 Verizon VERIZON MARYLAND, INC. – yes yes
443-537 Verizon CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD – yes yes
443-538 T-Mobile OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 2001-06-20 no yes
443-539 Windstream PAETEC ITEL, LLC – yes yes
443-542 Comcast COMCAST IP PHONE, LLC – yes yes
443-545 Lumen LEVEL 3 COMMUNICATIONS, LLC - MD 2001-05-18 yes yes
443-546 Verizon VERIZON MARYLAND, INC. – yes yes
443-583 Windstream PAETEC ITEL, LLC – yes yes
443-656 Windstream PAETEC ITEL, LLC 2001-05-10 yes yes
443-718 Windstream PAETEC ITEL, LLC 2008-03-05 yes yes
443-741 Verizon MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 2011-03-29 yes yes
443-745 Verizon CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD – no yes
443-766 Windstream PAETEC ITEL, LLC 2005-05-18 yes yes
443-774 AT&T NEW CINGULAR WIRELESS PCS, LLC - DC 2018-11-19 yes yes
443-812 Verizon CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 2001-01-15 yes yes
443-832 Lumen LEVEL 3 COMMUNICATIONS, LLC - MD – yes yes
443-864 T-Mobile METROPCS, INC. 2001-12-19 yes yes
443-878 Verizon CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD – yes yes
443-896 AT&T TELEPORT COMMUNICATIONS AMERICA, LLC - MD – yes yes
443-917 Onvoy ONVOY, LLC - MD 2011-10-07 yes yes
443-979 Verizon CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 2011-11-21 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
PAETEC ITEL, LLC Windstream 7 22.6%
VERIZON MARYLAND, INC. Verizon 6 19.4%
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD Verizon 5 16.1%
LEVEL 3 COMMUNICATIONS, LLC - MD Lumen 4 12.9%
MCIMETRO ACCESS TRANSMISSION SERVICES LLC Verizon 2 6.5%
OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC T-Mobile 1 3.2%
COMCAST IP PHONE, LLC Comcast 1 3.2%
MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD Verizon 1 3.2%
NEW CINGULAR WIRELESS PCS, LLC - DC AT&T 1 3.2%
METROPCS, INC. T-Mobile 1 3.2%
TELEPORT COMMUNICATIONS AMERICA, LLC - MD AT&T 1 3.2%
ONVOY, LLC - MD Onvoy 1 3.2%

Same rate center in other codes

Overlay codes cover the same geography, so one rate center is served by all of them.

Frequently asked

Which prefixes belong to COLUMBIA in area code 443?

31 blocks: 259, 276, 283, 285, 319, 367, 393, 430, 472, 518, 535, 537 and 19 more, all listed in the table above.

Which carriers have numbers in COLUMBIA?

PAETEC ITEL, LLC (7 blocks), VERIZON MARYLAND, INC. (6 blocks), CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD (5 blocks), LEVEL 3 COMMUNICATIONS, LLC - MD (4 blocks), MCIMETRO ACCESS TRANSMISSION SERVICES LLC (2 blocks), OMNIPOINT COMMUNICATIONS CAP OPERATIONS, 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 COLUMBIA 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 443

All 785 prefixes in 443