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 667
CORE COMMUNICATIONS, INC.- MD 41
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
2018-12-11 667-653 0–9 XXXall 10 · 5 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 BRYNPKLNCM MD
2018-12-10 667-326 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 CHURCHHILL MD
2018-12-10 667-843 0XXX1XXX2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 2 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 DEALISLAND MD
2018-10-22 667-267 0–9 XXXwhole prefix which blocks → CORE COMMUNICATIONS, INC.- MD 2593 ANNAPOLIS MD
2018-10-18 667-362 0–9 XXXwhole prefix which blocks → CORE COMMUNICATIONS, INC.- MD 2593 ANNAPOLIS MD
2018-10-18 667-627 0–9 XXXwhole prefix which blocks → CORE COMMUNICATIONS, INC.- MD 2593 ANNAPOLIS MD
2018-10-18 667-876 0–9 XXXwhole prefix which blocks → CORE COMMUNICATIONS, INC.- MD 2593 ANNAPOLIS MD
2018-10-16 667-382 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 2 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 WINGATE MD
2018-10-16 667-473 0–9 XXXall 10 · 3 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 SOLOMONS MD
2018-10-16 667-545 0–9 XXXall 10 · 2 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 WARWICK MD
2018-10-16 667-727 0–9 XXXall 10 · 3 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 SUDLERSVL MD
2018-10-16 667-837 0–9 XXXall 10 · 2 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 PT DEPOSIT MD
2018-10-15 667-269 0–9 XXXall 10 · 2 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 ELKTON MD
2018-10-15 667-295 0–9 XXXall 10 · 4 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 CROFTON MD
2018-10-15 667-332 0–9 XXXwhole prefix which blocks → CORE COMMUNICATIONS, INC.- MD 2593 NEWWINDSOR MD
2018-10-15 667-366 0–9 XXXall 10 · 2 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 HAMPSTEAD MD
2018-10-15 667-372 0–9 XXXall 10 · 4 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 CAMBRIDGE MD
2018-10-15 667-373 0–9 XXXwhole prefix which blocks → CORE COMMUNICATIONS, INC.- MD 2593 NORTHBEACH MD
2018-10-15 667-686 0–9 XXXall 10 · 4 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 ELLICOTTCY MD
2018-10-15 667-722 0–9 XXXall 10 · 2 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 GLENWOOD MD
2018-10-15 667-946 0–9 XXXall 10 · 2 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 CHURCHVL MD
2018-06-12 667-238 0–9 XXXall 10 · 2 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 PRESTON MD
2018-06-12 667-241 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 RIDGELY MD
2018-06-12 667-242 0–9 XXXall 10 · 2 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 ROCK HALL MD
2018-06-12 667-244 0–9 XXXall 10 · 3 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 STILL POND MD
2018-06-12 667-245 0–9 XXXall 10 · 2 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 CECILTON MD
2018-06-12 667-246 0–9 XXXwhole prefix which blocks → CORE COMMUNICATIONS, INC.- MD 2593 CENTREVL MD
2018-06-12 667-247 0–9 XXXall 10 · 2 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 CHESAPKECY MD
2018-06-12 667-248 0–9 XXXall 10 · 2 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 DENTON MD
2018-06-12 667-249 0XXX1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 GALENA MD
2018-06-11 667-236 0–9 XXXall 10 · 2 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 PERRYVILLE MD
2018-06-11 667-237 0XXX1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 WEST RIVER MD
2018-06-04 667-243 0–9 XXXall 10 · 2 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 OXFORD MD
2018-06-04 667-345 0–9 XXXall 10 · 5 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 CATONSVL MD
2018-06-04 667-364 0–9 XXXall 10 · 3 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 STEVENSVL MD
2018-06-04 667-866 0–9 XXXall 10 · 3 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 DARLINGTON MD
2018-06-01 667-300 0–9 XXXall 10 · 3 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 COLUMBIA MD
2018-06-01 667-336 0–9 XXXall 10 · 3 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 BEL AIR MD
2018-06-01 667-500 0–9 XXXall 10 · 2 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 ANNAPOLIS MD
2018-05-31 667-277 0–9 XXXwhole prefix which blocks → CORE COMMUNICATIONS, INC.- MD 2593 SHERWD FOR MD
— 667-254 0–9 XXXall 10 · 5 holders which blocks → CORE COMMUNICATIONS, INC.- MD 2593 CHESTERTN 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.