NumberResearch Membership · Data 09/20/2026

Recent prefix assignments

0 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/20/2026

Full prefixes (NXX) Thousands-blocks (1,000-number pools)

The Code holder is who opened each NPA-NXX prefix — not necessarily who holds the numbers. A prefix is 10,000 numbers, but under pooling its ten 1,000-number blocks are handed out individually, often to different carriers; the code holder may hold only one block, or none. The Thousands-blocks column shows how the ten blocks are really split — click which blocks → to see who holds each 1,000-number block and its last-4-digit range. Assignments are initial assignments; the current serving carrier may differ due to portability.

Most active assignees, all time — NPA 443
CORE COMMUNICATIONS, INC.- MD 34
New assignments by month Sep 2026 Aug 2026 Jul 2026 Jun 2026 May 2026 Apr 2026 Mar 2026 Feb 2026 Jan 2026 Dec 2025 Nov 2025 Oct 2025
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Recent NPA-NXX prefix assignments
AssignedNPA-NXXThousands-blocks taken (last-4 opening)Code holderOCNRate centerState
2002-07-02 443-856 0–9 XXXall 10 · 3 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 OCEAN CITY MD
2002-07-02 443-912 0–9 XXXall 10 · 3 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 TOWSON MD
2002-02-22 443-747 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 8 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 PT DEPOSIT MD
— 443-215 not yet reported which blocks → CORE COMMUNICATIONS, INC.- MD 2593 CHESTERTN MD
— 443-217 not yet reported which blocks → CORE COMMUNICATIONS, INC.- MD 2593 ANNAPOLIS MD
— 443-232 0–9 XXXall 10 · 4 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 WILLARDS MD
— 443-236 not yet reported which blocks → CORE COMMUNICATIONS, INC.- MD 2593 CARDIFF MD
— 443-237 not yet reported which blocks → CORE COMMUNICATIONS, INC.- MD 2593 NORTHBEACH MD
— 443-246 not yet reported which blocks → CORE COMMUNICATIONS, INC.- MD 2593 ELKTON MD
— 443-264 0–9 XXXall 10 · 5 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 PIKESVILLE MD
— 443-268 not yet reported which blocks → CORE COMMUNICATIONS, INC.- MD 2593 BALTIMORE MD
— 443-269 0–9 XXXall 10 · 4 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 TOWSON MD
— 443-284 0XXX1XXX2XXX3XXX5XXX6XXX7XXX · 2 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 WATERLO238 MD
— 443-337 0–9 XXXall 10 · 2 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 SPARROWSPT MD
— 443-344 not yet reported which blocks → CORE COMMUNICATIONS, INC.- MD 2593 SEVERNA PK MD
— 443-346 0–9 XXXall 10 · 3 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 SEVERNA PK MD
— 443-349 not yet reported which blocks → CORE COMMUNICATIONS, INC.- MD 2593 SILVER RUN MD
— 443-361 not yet reported which blocks → CORE COMMUNICATIONS, INC.- MD 2593 SYKESVILLE MD
— 443-363 0–9 XXXall 10 · 4 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 SEVERN MD
— 443-368 not yet reported which blocks → CORE COMMUNICATIONS, INC.- MD 2593 WESTMINSTR MD
— 443-369 not yet reported which blocks → CORE COMMUNICATIONS, INC.- MD 2593 BEL AIR MD
— 443-382 not yet reported which blocks → CORE COMMUNICATIONS, INC.- MD 2593 CAMBRIDGE MD
— 443-385 not yet reported which blocks → CORE COMMUNICATIONS, INC.- MD 2593 EASTON MD
— 443-387 not yet reported which blocks → CORE COMMUNICATIONS, INC.- MD 2593 POCOMOKE MD
— 443-389 not yet reported which blocks → CORE COMMUNICATIONS, INC.- MD 2593 SALISBURY MD
— 443-427 not yet reported which blocks → CORE COMMUNICATIONS, INC.- MD 2593 PRINCEANNE MD
— 443-428 not yet reported which blocks → CORE COMMUNICATIONS, INC.- MD 2593 COCKEYSVL MD
— 443-431 0–9 XXXall 10 · 4 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 RANDALLSTN MD
— 443-586 0–9 XXXall 10 · 3 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 DUNDALK MD
— 443-592 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 ELKRIDGE MD
— 443-596 0–9 XXXall 10 · 5 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 ESSEX MD
— 443-628 0–9 XXXall 10 · 4 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 GLENBURNIE MD
— 443-665 0–9 XXXall 10 · 4 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 NANTICOKE MD
— 443-946 0–9 XXXall 10 · 5 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 PARKVILLE MD

Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/20/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.