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

NORTHBEACH prefixes in area code 443

NANPA records 4 assigned NXX blocks to rate center NORTHBEACH in area code 443, 0.5% 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. 3 holders hold those blocks, the largest being LEVEL 3 COMMUNICATIONS, LLC - MD (2), CORE COMMUNICATIONS, INC.- MD (1), PAETEC ITEL, LLC (1). The earliest assignment on record here is 2006-05-12 and the most recent 2006-05-12. 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 410, 667 – overlay codes cover the same geography, so a rate center is served by all of them.

4 assigned blocks – 0.5% of 443
3 holders of record
3 of them pooled in 1,000-number lots

Prefixes assigned here

PrefixHolder of recordAssignedPooledIn service
443-237 CORE COMMUNICATIONS, INC.- MD – no yes
443-550 Lumen LEVEL 3 COMMUNICATIONS, LLC - MD – yes yes
443-646 Windstream PAETEC ITEL, LLC – yes yes
443-964 Lumen LEVEL 3 COMMUNICATIONS, LLC - MD 2006-05-12 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
LEVEL 3 COMMUNICATIONS, LLC - MD Lumen 2 50%
CORE COMMUNICATIONS, INC.- MD – 1 25%
PAETEC ITEL, LLC Windstream 1 25%

Frequently asked

Which prefixes belong to NORTHBEACH in area code 443?

4 blocks: 237, 550, 646, 964. The table above gives the holder of each.

Which carriers have numbers in NORTHBEACH?

LEVEL 3 COMMUNICATIONS, LLC - MD (2 blocks), CORE COMMUNICATIONS, INC.- MD (1 block), PAETEC ITEL, 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 NORTHBEACH 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