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

CAMBRIDGE prefixes in area code 410

NANPA records 4 assigned NXX blocks to rate center CAMBRIDGE in area code 410, 0.5% of the 783 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. 2 holders hold those blocks, the largest being VERIZON MARYLAND, INC. (3), NEW CINGULAR WIRELESS PCS, LLC - DC (1). 2 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 208, 308, 309, 443 – overlay codes cover the same geography, so a rate center is served by all of them.

4 assigned blocks – 0.5% of 410
2 holders of record
2 of them pooled in 1,000-number lots

Prefixes assigned here

PrefixHolder of recordAssignedPooledIn service
410-221 Verizon VERIZON MARYLAND, INC. – no yes
410-228 Verizon VERIZON MARYLAND, INC. – no yes
410-330 AT&T NEW CINGULAR WIRELESS PCS, LLC - DC – yes yes
410-901 Verizon VERIZON MARYLAND, INC. – 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
VERIZON MARYLAND, INC. Verizon 3 75%
NEW CINGULAR WIRELESS PCS, LLC - DC AT&T 1 25%

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 CAMBRIDGE in area code 410?

4 blocks: 221, 228, 330, 901. The table above gives the holder of each.

Which carriers have numbers in CAMBRIDGE?

VERIZON MARYLAND, INC. (3 blocks), NEW CINGULAR WIRELESS PCS, LLC - DC (1 block). These are the holders on record; the carrier actually serving a given number can differ, because numbers move with their owners.

Is CAMBRIDGE 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 410

All 783 prefixes in 410