NumberResearch Membership · Data 09/19/2026

Recent prefix assignments

4 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/19/2026

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
2021-03-19 667-306 0–9 XXXwhole prefix which blocks → LEVEL 3 COMMUNICATIONS, LLC - MD 6119 BALTIMORE MD
2021-03-18 667-327 0–9 XXXall 10 · 4 holders which blocks → ONVOY, LLC - MD 876D CAMBRIDGE MD
2021-03-18 667-337 0–9 XXXall 10 · 6 holders which blocks → ONVOY, LLC - MD 876D CENTREVL MD
2021-03-18 667-347 0–9 XXXall 10 · 4 holders which blocks → ONVOY, LLC - MD 876D FEDERALSBG MD
2021-03-18 667-357 0XXX2XXX3XXX4XXX5XXX6XXX7XXX9XXX · 3 holders which blocks → ONVOY, LLC - MD 876D GREENSBORO MD
2021-03-18 667-376 0XXX1XXX2XXX3XXX5XXX6XXX7XXX · 3 holders which blocks → ONVOY, LLC - MD 876D OXFORD MD
2021-03-18 667-377 2XXX3XXX4XXX5XXX6XXX7XXX · 2 holders which blocks → ONVOY, LLC - MD 876D ROCK HALL MD
2021-03-18 667-670 0XXX1XXX3XXX6XXX7XXX8XXX · 3 holders which blocks → ONVOY, LLC - MD 876D SUDLERSVL MD
2021-03-18 667-687 0XXX4XXX6XXX7XXX8XXX · 5 holders which blocks → ONVOY, LLC - MD 876D WARWICK MD
2021-03-18 667-766 1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → ONVOY, LLC - MD 876D STEVENSVL MD
2021-03-18 667-767 0–9 XXXall 10 · 4 holders which blocks → ONVOY, LLC - MD 876D STMICHAELS MD
2021-03-18 667-848 0–9 XXXall 10 · 4 holders which blocks → TON80 COMMUNICATIONS, LLC 516J ABERDEEN MD
2021-03-03 667-810 5XXX6XXX7XXX8XXX which blocks → ONVOY, LLC - MD 876D SALISBURY MD
2021-03-03 667-910 0–9 XXXall 10 · 3 holders which blocks → ONVOY, LLC - MD 876D BALTIMORE MD
2021-02-22 667-304 0–9 XXXall 10 · 6 holders which blocks → BANDWIDTH.COM CLEC, LLC - MD 071F ESSEX MD
2021-02-11 667-646 0–9 XXXall 10 · 5 holders which blocks → TON80 COMMUNICATIONS, LLC 516J ANNAPOLIS MD
2021-02-09 667-302 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → TELNYX LLC 073H CECILTON MD
2021-01-25 667-301 0–9 XXXall 10 · 5 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 PRINCEFRCK MD
2021-01-18 667-298 0–9 XXXall 10 · 2 holders which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 ABERDEEN MD
2020-12-09 667-297 0–9 XXXall 10 · 4 holders which blocks → METROPCS, INC. 5562 EDGEWOOD MD
2020-10-15 667-895 0–9 XXXall 10 · 7 holders which blocks → TWILIO INTERNATIONAL, INC. 506J BALTIMORE MD
2020-09-22 667-296 0–9 XXXall 10 · 2 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 7228 REISTERSTN MD
2020-09-21 667-293 1XXX3XXX4XXX5XXX6XXX7XXX9XXX · 4 holders which blocks → ONVOY, LLC - MD 876D SHARPTOWN MD
2020-09-21 667-294 0–9 XXXall 10 · 6 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 TOWSON MD
2020-09-21 667-676 0XXX1XXX2XXX4XXX6XXX7XXX8XXX · 3 holders which blocks → ONVOY, LLC - MD 876D WILLARDS MD
2020-09-09 667-290 0–9 XXXall 10 · 3 holders which blocks → IP HORIZON LLC 515J BALTIMORE MD
2020-09-09 667-292 0XXX1XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → IP HORIZON LLC 515J SALISBURY MD
2020-09-01 667-287 0–9 XXXall 10 · 4 holders which blocks → NUSO, LLC 478J BISHOPVL MD
2020-09-01 667-288 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX9XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MD 6119 BERLIN MD
2020-09-01 667-289 0–9 XXXall 10 · 2 holders which blocks → OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 6855 ABERDEEN MD
2020-08-12 667-286 0XXX1XXX2XXX3XXX4XXX7XXX8XXX9XXX · 3 holders which blocks → HD CARRIER LLC 321J SALISBURY MD
2020-07-30 667-284 0–9 XXXall 10 · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MD 6119 BALTIMORE MD
2020-07-15 667-577 0–9 XXXall 10 · 5 holders which blocks → FRACTEL, LLC 965H ELKTON MD
2020-07-15 667-688 0–9 XXXall 10 · 6 holders which blocks → FRACTEL, LLC 965H PARKVILLE MD
2020-07-15 667-758 0XXX1XXX2XXX3XXX4XXX6XXX8XXX9XXX · 4 holders which blocks → FRACTEL, LLC 965H SILVER RUN MD
2020-07-15 667-842 0–9 XXXall 10 · 7 holders which blocks → FRACTEL, LLC 965H WOODLAWN MD
2020-07-06 667-283 0–9 XXXall 10 · 6 holders which blocks → AT&T - LOCAL 7421 FORK MD
2020-07-02 667-977 0–9 XXXall 10 · 3 holders which blocks → FRACTEL, LLC 965H SALISBURY MD
2020-05-28 667-282 1XXX2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 2 holders which blocks → ONVOY, LLC - MD 876D TILGHMAN MD
2020-05-05 667-280 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → VONAGE AMERICA LLC 197D ELLICOTTCY MD
2020-04-10 667-299 0–9 XXXall 10 · 5 holders which blocks → HD CARRIER LLC 321J ANNAPOLIS MD
2020-04-10 667-399 0XXX1XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → HD CARRIER LLC 321J UNION BDG MD
2020-03-12 667-279 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → ONVOY, LLC - MD 876D BISHOPVL MD
2020-03-09 667-263 0–9 XXXall 10 · 5 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 DUNDALK MD
2020-03-09 667-278 0–9 XXXall 10 · 2 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 TOWSON MD
2020-01-27 667-276 0–9 XXXall 10 · 5 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD 7228 BEL AIR MD
2019-12-24 667-261 0–9 XXXall 10 · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 COLUMBIA MD
2019-11-01 667-275 0–9 XXXall 10 · 5 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD 6395 TOWSON MD
2019-10-15 667-346 0XXX2XXX3XXX6XXX7XXX9XXX · 4 holders which blocks → CSC WIRELESS, LLC 425J SALISBURY MD
2019-10-11 667-274 0–9 XXXall 10 · 5 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - DC 4036 ELKRIDGE MD

Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/19/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.