NumberResearch Membership · Data 09/20/2026

Recent prefix assignments

4 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, last 30 days — NPA 667
NEW CINGULAR WIRELESS PCS, LLC - DC 2
ONVOY, LLC - MD 1
METROPCS, INC. 1
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
2019-10-10 667-660 4XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → ONVOY, LLC - MD 876D MARION MD
2019-10-10 667-661 2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → ONVOY, LLC - MD 876D SNOW HILL MD
2019-10-10 667-662 0XXX1XXX2XXX4XXX6XXX7XXX9XXX · 4 holders which blocks → ONVOY, LLC - MD 876D SMITH IS MD
2019-10-10 667-663 0–9 XXXall 10 · 4 holders which blocks → ONVOY, LLC - MD 876D OCEAN CITY MD
2019-10-10 667-664 0XXX2XXX4XXX6XXX7XXX9XXX · 4 holders which blocks → ONVOY, LLC - MD 876D TRAPPE MD
2019-10-09 667-273 0–9 XXXall 10 · 4 holders which blocks → CSC WIRELESS, LLC 425J PIKESVILLE MD
2019-09-24 667-776 0–9 XXXall 10 · 3 holders which blocks → HD CARRIER LLC 321J BALTIMORE MD
2019-09-18 667-272 0–9 XXXall 10 · 5 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 WESTMINSTR MD
2019-09-12 667-353 0XXX1XXX2XXX4XXX5XXX7XXX8XXX9XXX · 6 holders which blocks → CORETEL MARYLAND, INC. - MD 469J CARDIFF MD
2019-09-12 667-853 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → CORETEL MARYLAND, INC. - MD 469J POCOMOKE MD
2019-09-03 667-271 0XXX1XXX3XXX4XXX8XXX9XXX · 4 holders which blocks → EXIANT COMMUNICATIONS LLC 114J SALISBURY MD
2019-08-16 667-270 0–9 XXXall 10 · 6 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 ANNAPOLIS MD
2019-06-19 667-268 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → BANDWIDTH.COM CLEC, LLC - MD 071F DARLINGTON MD
2019-03-22 667-265 0–9 XXXall 10 · 4 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 VIENNA MD
2019-02-22 667-855 0XXX2XXX4XXX5XXX7XXX8XXX9XXX · 4 holders which blocks → TERRA NOVA TELECOM INC. 145J SALISBURY MD
2019-02-20 667-264 0–9 XXXall 10 · 5 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 7228 DELMAR MD
2019-02-20 667-900 0–9 XXXall 10 · 5 holders which blocks → TERRA NOVA TELECOM INC. 145J BALTIMORE MD
2018-12-21 667-259 0–9 XXXall 10 · 2 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 7228 REISTERSTN MD
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
2018-11-14 667-257 0–9 XXXall 10 · 5 holders which blocks → VONAGE AMERICA LLC 197D COLUMBIA MD
2018-11-14 667-258 0–9 XXXall 10 · 2 holders which blocks → AIRESPRING, INC. 996H BALTIMORE 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
2018-09-27 667-256 0–9 XXXall 10 · 5 holders which blocks → EXIANT COMMUNICATIONS LLC 114J ABERDEEN MD
2018-08-22 667-255 0XXX1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → ONVOY, LLC - MD 876D HILLSBORO MD
2018-06-19 667-250 0–9 XXXall 10 · 2 holders which blocks → ONVOY SPECTRUM, LLC 624H BALTIMORE MD
2018-06-19 667-252 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → ONVOY SPECTRUM, LLC 624H SALISBURY 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

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.