NumberResearch Membership · Data 09/19/2026

Recent prefix assignments

1 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 531
MIDSTATES DATA TRANSPORT, LLC - NE 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
2021-03-08 531-400 0–9 XXXall 10 · 6 holders which blocks → ONVOY, LLC - NE 549E COLUMBUS NE
2021-03-05 531-254 0–9 XXXall 10 · 3 holders which blocks → ALLO COMMUNICATIONS LLC 907K LINCOLN NE
2021-03-04 531-255 0–9 XXXall 10 · 4 holders which blocks → CHARTER IP ENABLED SERVICES, LLC 792K OMAHA NE
2021-02-09 531-559 0–9 XXXall 10 · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - NE 3233 OMAHA NE
2021-01-29 531-256 0–9 XXXwhole prefix which blocks → COMCAST IP PHONE, LLC 318J OMAHA NE
2020-12-17 531-252 0XXX1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → BANDWIDTH.COM CLEC, LLC - NE 995E CRESTON NE
2020-10-26 531-250 0–9 XXXall 10 · 3 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - NE 5807 OMAHA NE
2020-10-26 531-353 0–9 XXXall 10 · 5 holders which blocks → ONVOY, LLC - NE 549E WAHOO NE
2020-10-22 531-895 0–9 XXXall 10 · 4 holders which blocks → TWILIO INTERNATIONAL, INC. 506J OMAHA NE
2020-10-15 531-266 0XXX3XXX4XXX9XXX · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 RUSKIN NE
2020-08-17 531-900 0XXX1XXX2XXX3XXX4XXX6XXX7XXX9XXX · 6 holders which blocks → FRACTEL, LLC 965H WEST POINT NE
2020-07-06 531-249 0–9 XXXall 10 · 4 holders which blocks → VONAGE AMERICA LLC 197D LINCOLN NE
2020-06-29 531-247 0–9 XXXall 10 · 5 holders which blocks → CSC WIRELESS, LLC 425J OMAHA NE
2020-06-04 531-246 0–9 XXXall 10 · 7 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 SUPERIOR NE
2020-06-03 531-245 0XXX2XXX3XXX4XXX9XXX · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 HARVARD NE
2020-05-21 531-243 4XXX5XXX9XXX · 2 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 BRUNING NE
2020-05-20 531-241 0–9 XXXwhole prefix which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - NE 7144 OMAHA NE
2020-04-03 531-253 0XXX1XXX2XXX3XXX4XXX5XXX9XXX · 4 holders which blocks → ONVOY, LLC - NE 549E OTOE NE
2020-04-03 531-534 0XXX3XXX4XXX5XXX6XXX · 2 holders which blocks → ONVOY, LLC - NE 549E DEWEESE NE
2020-04-03 531-551 0XXX3XXX4XXX5XXX6XXX9XXX · 3 holders which blocks → ONVOY, LLC - NE 549E DUNBAR NE
2020-04-02 531-272 0–9 XXXall 10 · 6 holders which blocks → METROPCS, INC. 5562 OMAHA NE
2020-03-24 531-242 0–9 XXXall 10 · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - NE 5807 OMAHA NE
2020-02-13 531-240 0–9 XXXall 10 · 8 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - NE 5807 ASHLAND NE
2019-11-15 531-541 0–9 XXXall 10 · 5 holders which blocks → WIDE VOICE, LLC - NE 444H OMAHA NE
2019-10-29 531-510 0–9 XXXall 10 · 4 holders which blocks → ONVOY SPECTRUM, LLC 624H LINCOLN NE
2019-10-24 531-710 0–9 XXXall 10 · 4 holders which blocks → ONVOY SPECTRUM, LLC 624H OMAHA NE
2019-08-23 531-238 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → ONVOY, LLC - NE 549E RANDOLPH NE
2019-08-22 531-235 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → ONVOY, LLC - NE 549E EMERSON NE
2019-08-22 531-236 1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → ONVOY, LLC - NE 549E HUMPHREY NE
2019-08-22 531-237 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → ONVOY, LLC - NE 549E PENDER NE
2019-07-18 531-230 0–9 XXXall 10 · 4 holders which blocks → ONVOY, LLC - NE 549E COLUMBUS NE
2019-06-25 531-625 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 SOSIOUX CY NE
2019-06-20 531-239 0–9 XXXall 10 · 4 holders which blocks → METROPCS, INC. 5562 OMAHA NE
2019-06-20 531-867 0–9 XXXall 10 · 6 holders which blocks → COMMIO, LLC 939H OMAHA NE
2019-06-10 531-232 0–9 XXXwhole prefix which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 OMAHA NE
2019-05-01 531-221 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → ONVOY, LLC - NE 549E SO YANKTON NE
2019-03-07 531-331 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX · 3 holders which blocks → ONVOY, LLC - NE 549E MARTELL NE
2019-03-07 531-351 3XXX5XXX6XXX which blocks → ONVOY, LLC - NE 549E TABLE ROCK NE
2019-03-07 531-535 0XXX2XXX3XXX4XXX5XXX6XXX7XXX · 2 holders which blocks → ONVOY, LLC - NE 549E KENESAW NE
2019-03-06 531-231 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX · 4 holders which blocks → ONVOY, LLC - NE 549E CLAYCENTER NE
2019-03-06 531-251 0–9 XXXall 10 · 6 holders which blocks → ONVOY, LLC - NE 549E DAWSON NE
2019-03-06 531-521 0XXX3XXX4XXX5XXX · 2 holders which blocks → ONVOY, LLC - NE 549E DAVEY NE
2019-03-06 531-533 0–9 XXXall 10 · 6 holders which blocks → ONVOY, LLC - NE 549E GUIDE ROCK NE
2019-02-15 531-530 0–9 XXXall 10 · 4 holders which blocks → ONVOY, LLC - NE 549E LINCOLN NE
2019-02-14 531-321 0XXX1XXX2XXX3XXX4XXX5XXX6XXX · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - NE 5807 ADAMS NE
2019-01-28 531-666 0–9 XXXall 10 · 6 holders which blocks → FRACTEL, LLC 965H FREMONT NE
2019-01-28 531-800 0–9 XXXall 10 · 5 holders which blocks → FRACTEL, LLC 965H OMAHA NE
2019-01-11 531-999 0–9 XXXall 10 · 4 holders which blocks → TERRA NOVA TELECOM INC. 145J OMAHA NE
2018-12-04 531-229 0–9 XXXall 10 · 4 holders which blocks → AERIAL COMMUNICATIONS, INC. 6701 LINCOLN NE
2018-11-07 531-228 0XXX1XXX2XXX4XXX8XXX9XXX · 3 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - NE 5807 PLATTSMTH NE

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.