NumberResearch Membership · Data 09/19/2026

Recent prefix assignments

0 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, all time — NPA 623
QWEST CORPORATION 97
T-MOBILE USA, INC. 39
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AZ 31
ONVOY, LLC - AZ 29
NEW CINGULAR WIRELESS PCS, LLC 22
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
Clear Download CSV ↓
Recent NPA-NXX prefix assignments
AssignedNPA-NXXThousands-blocks taken (last-4 opening)Code holderOCNRate centerState
2026-08-14 623-310 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX · 2 holders which blocks → ONVOY, LLC - AZ 630E PHOENIX AZ
2026-08-07 623-438 2XXX3XXX4XXX8XXX9XXX · 2 holders which blocks → AHOI LLC 883K PHOENIX AZ
2026-04-20 623-373 0–9 XXXall 10 · 2 holders which blocks → VOIP INNOVATIONS, LLC 597F PHOENIX AZ
2025-10-22 623-955 0XXX1XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → ALLO COMMUNICATIONS LLC 907K PHOENIX AZ
2025-05-05 623-456 0–9 XXXall 10 · 2 holders which blocks → BOOST SUBSCRIBERCO L.L.C. 490J PHOENIX AZ
2024-07-17 623-260 0–9 XXXall 10 · 3 holders which blocks → ONVOY, LLC - AZ 630E PHOENIX AZ
2024-02-23 623-220 0–9 XXXall 10 · 2 holders which blocks → ONVOY, LLC - AZ 630E PHOENIX AZ
2023-06-12 623-309 0–9 XXXall 10 · 4 holders which blocks → ONVOY SPECTRUM, LLC 624H PHOENIX AZ
2023-04-18 623-307 0–9 XXXall 10 · 4 holders which blocks → ALLO COMMUNICATIONS LLC 907K PHOENIX AZ
2023-03-09 623-305 0–9 XXXall 10 · 2 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC 6010 PHOENIX AZ
2023-01-11 623-212 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 PHOENIX AZ
2022-11-23 623-290 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 PHOENIX AZ
2022-10-04 623-352 0–9 XXXwhole prefix which blocks → ONVOY, LLC - AZ 630E PHOENIX AZ
2022-09-23 623-301 0–9 XXXall 10 · 3 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AZ 6572 PHOENIX AZ
2022-09-21 623-291 0–9 XXXall 10 · 3 holders which blocks → NUSO, LLC 732J PHOENIX AZ
2022-09-20 623-320 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 PHOENIX AZ
2022-09-01 623-343 0–9 XXXwhole prefix which blocks → ONVOY, LLC - AZ 630E PHOENIX AZ
2022-09-01 623-462 0–9 XXXwhole prefix which blocks → ONVOY, LLC - AZ 630E PHOENIX AZ
2022-08-31 623-324 0–9 XXXall 10 · 3 holders which blocks → ONVOY SPECTRUM, LLC 624H PHOENIX AZ
2022-07-15 623-294 0–9 XXXwhole prefix which blocks → ONVOY, LLC - AZ 630E PHOENIX AZ
2022-07-14 623-286 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 PHOENIX AZ
2022-06-14 623-287 0–9 XXXall 10 · 2 holders which blocks → COMMIO, LLC 939H PHOENIX AZ
2022-06-03 623-304 0–9 XXXwhole prefix which blocks → ONVOY, LLC - AZ 630E PHOENIX AZ
2022-04-22 623-276 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 PHOENIX AZ
2022-04-11 623-283 0–9 XXXall 10 · 3 holders which blocks → ONVOY, LLC - AZ 630E PHOENIX AZ
2022-02-22 623-284 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 PHOENIX AZ
2022-02-22 623-288 0–9 XXXwhole prefix which blocks → ONVOY, LLC - AZ 630E PHOENIX AZ
2022-01-13 623-281 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 PHOENIX AZ
2021-12-02 623-280 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 PHOENIX AZ
2021-11-12 623-279 0–9 XXXwhole prefix which blocks → ONVOY SPECTRUM, LLC 624H PHOENIX AZ
2021-10-07 623-274 0–9 XXXall 10 · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - AZ 3285 PHOENIX AZ
2021-10-04 623-278 0–9 XXXall 10 · 3 holders which blocks → TELNYX LLC 073H PHOENIX AZ
2021-09-14 623-275 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 PHOENIX AZ
2021-08-12 623-624 0–9 XXXwhole prefix which blocks → ONVOY, LLC - AZ 630E PHOENIX AZ
2021-07-01 623-273 0–9 XXXall 10 · 3 holders which blocks → T-MOBILE USA, INC. 6529 PHOENIX AZ
2021-04-21 623-887 0–9 XXXwhole prefix which blocks → ONVOY, LLC - AZ 630E PHOENIX AZ
2021-03-30 623-270 0–9 XXXall 10 · 3 holders which blocks → COMCAST IP PHONE, LLC 318J PHOENIX AZ
2021-03-25 623-268 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 PHOENIX AZ
2021-02-03 623-920 0–9 XXXall 10 · 2 holders which blocks → ONVOY, LLC - AZ 630E PHOENIX AZ
2020-12-10 623-272 0–9 XXXwhole prefix which blocks → T-MOBILE USA, INC. 6529 PHOENIX AZ
2020-12-09 623-269 0–9 XXXall 10 · 5 holders which blocks → COMCAST IP PHONE, LLC 318J PHOENIX AZ
2020-11-18 623-267 0–9 XXXall 10 · 2 holders which blocks → TON80 COMMUNICATIONS, LLC 516J PHOENIX AZ
2020-11-09 623-303 0–9 XXXwhole prefix which blocks → ONVOY, LLC - AZ 630E PHOENIX AZ
2020-09-24 623-356 0–9 XXXall 10 · 3 holders which blocks → FRACTEL, LLC 965H PHOENIX AZ
2020-09-15 623-264 0–9 XXXall 10 · 2 holders which blocks → T-MOBILE USA, INC. 6529 PHOENIX AZ
2020-09-08 623-265 0–9 XXXall 10 · 3 holders which blocks → CENTURYLINK COMMUNICATIONS, LLC 508J PHOENIX AZ
2020-09-02 623-292 0–9 XXXall 10 · 2 holders which blocks → METROPCS, INC. 5562 PHOENIX AZ
2020-07-14 623-400 0–9 XXXall 10 · 3 holders which blocks → FRACTEL, LLC 965H PHOENIX AZ
2020-06-22 623-632 0–9 XXXall 10 · 3 holders which blocks → ONVOY SPECTRUM, LLC 624H PHOENIX AZ
2020-06-19 623-257 0–9 XXXall 10 · 2 holders which blocks → BANDWIDTH.COM CLEC, LLC - AZ 587F PHOENIX AZ

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.