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

BALTIMORE prefixes in area code 740

NANPA records 3 assigned NXX blocks to rate center BALTIMORE in area code 740, 0.4% of the 786 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. 3 holders hold those blocks, the largest being TWC IP ENABLED SERVICES, LLC (1), NEW CINGULAR WIRELESS PCS, LLC - IL (1), FRONTIER NORTH, INC. - OH (1). The earliest assignment on record here is 2006-04-15 and the most recent 2022-08-26. 3 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 220, 301, 410, 443 – overlay codes cover the same geography, so a rate center is served by all of them.

3 assigned blocks – 0.4% of 740
3 holders of record
3 of them pooled in 1,000-number lots

Prefixes assigned here

PrefixHolder of recordAssignedPooledIn service
740-400 Charter TWC IP ENABLED SERVICES, LLC 2006-04-15 yes yes
740-556 AT&T NEW CINGULAR WIRELESS PCS, LLC - IL 2022-08-26 yes yes
740-862 Frontier FRONTIER NORTH, INC. - OH – 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
TWC IP ENABLED SERVICES, LLC Charter 1 33.3%
NEW CINGULAR WIRELESS PCS, LLC - IL AT&T 1 33.3%
FRONTIER NORTH, INC. - OH Frontier 1 33.3%

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 BALTIMORE in area code 740?

3 blocks: 400, 556, 862. The table above gives the holder of each.

Which carriers have numbers in BALTIMORE?

TWC IP ENABLED SERVICES, LLC (1 block), NEW CINGULAR WIRELESS PCS, LLC - IL (1 block), FRONTIER NORTH, INC. - OH (1 block). These are the holders on record; the carrier actually serving a given number can differ, because numbers move with their owners.

Is BALTIMORE 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 740

All 786 prefixes in 740