NumberResearch Membership · Data 09/19/2026

Recent prefix assignments

5 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 435
UINTAH BASIN ELECTRONIC TELECOMMUNICATIONS 4
TDS BROADBAND SERVICE LLC 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
2021-07-01 435-600 0XXX1XXX3XXX6XXX8XXX9XXX · 4 holders which blocks → FRACTEL, LLC 965H PAROWAN UT
2021-07-01 435-667 0–9 XXXall 10 · 6 holders which blocks → FRACTEL, LLC 965H BRIGHAM CY UT
2021-04-26 435-309 0–9 XXXall 10 · 6 holders which blocks → ONVOY, LLC - UT 871E GLNCNYONCY UT
2021-04-18 435-297 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - UT 6571 KAMAS UT
2021-04-12 435-547 0XXX1XXX2XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → TON80 COMMUNICATIONS, LLC 516J BRIAN HEAD UT
2021-02-01 435-352 0–9 XXXall 10 · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - UT 6571 HEBER CITY UT
2021-01-28 435-302 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - UT 6571 KAMAS UT
2021-01-26 435-303 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - UT 6571 BEARRIV CY UT
2021-01-25 435-281 0–9 XXXall 10 · 4 holders which blocks → NUSO, LLC 478J WASATCH UT
2021-01-12 435-274 0–9 XXXall 10 · 5 holders which blocks → ONVOY, LLC - UT 871E TOOELE UT
2020-12-29 435-278 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - UT 6571 ENTERPRISE UT
2020-11-24 435-523 0–9 XXXall 10 · 6 holders which blocks → ONVOY, LLC - UT 871E ST GEORGE UT
2020-11-09 435-534 0–9 XXXall 10 · 5 holders which blocks → ONVOY, LLC - UT 871E LOGAN UT
2020-10-07 435-290 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - UT 6571 KAMAS UT
2020-05-12 435-293 0–9 XXXwhole prefix which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - UT 6571 KAMAS UT
2020-04-20 435-334 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → ONVOY, LLC - UT 871E FILLMORE UT
2019-06-03 435-900 0–9 XXXall 10 · 5 holders which blocks → FRACTEL, LLC 965H ST GEORGE UT
2019-05-01 435-295 0–9 XXXall 10 · 6 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - UT 6571 BRIGHAM CY UT
2019-04-25 435-500 0–9 XXXall 10 · 5 holders which blocks → ONVOY, LLC - UT 871E DELTA UT
2019-03-06 435-296 0–9 XXXall 10 · 4 holders which blocks → PEERLESS NETWORK OF UTAH, LLC - UT 526H GLNCNYONCY UT
2019-03-05 435-271 0XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → PEERLESS NETWORK OF UTAH, LLC - UT 526H SALINA UT
2019-03-05 435-289 0–9 XXXall 10 · 7 holders which blocks → PEERLESS NETWORK OF UTAH, LLC - UT 526H RICHFIELD UT
2019-01-24 435-666 0–9 XXXall 10 · 7 holders which blocks → FRACTEL, LLC 965H PARK CITY UT
2019-01-23 435-264 0–9 XXXwhole prefix which blocks → ONVOY, LLC - UT 871E NAT BRIDGE UT
2019-01-23 435-269 0XXX1XXX2XXX3XXX4XXX5XXX9XXX · 2 holders which blocks → ONVOY, LLC - UT 871E BLUFF UT
2019-01-23 435-280 0XXX2XXX4XXX8XXX · 2 holders which blocks → ONVOY, LLC - UT 871E MEXICANHAT UT
2019-01-23 435-284 3XXX4XXX6XXX8XXX · 2 holders which blocks → ONVOY, LLC - UT 871E KANOSH UT
2019-01-23 435-325 2XXX3XXX4XXX5XXX8XXX which blocks → ONVOY, LLC - UT 871E MEADOW UT
2019-01-23 435-337 2XXX3XXX4XXX6XXX7XXX · 3 holders which blocks → ONVOY, LLC - UT 871E LAKEPOWELL UT
2019-01-23 435-344 0XXX2XXX3XXX4XXX5XXX · 2 holders which blocks → ONVOY, LLC - UT 871E LA SAL UT
2019-01-23 435-345 4XXX5XXX6XXX which blocks → ONVOY, LLC - UT 871E THOMPSON UT
2019-01-23 435-432 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX · 3 holders which blocks → ONVOY, LLC - UT 871E PROMONTORY UT
2019-01-23 435-441 1XXX2XXX3XXX4XXX5XXX which blocks → ONVOY, LLC - UT 871E HOLDEN UT
2019-01-23 435-495 2XXX4XXX5XXX which blocks → ONVOY, LLC - UT 871E OAK CITY UT
2018-12-20 435-375 0–9 XXXall 10 · 7 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC 6010 ST GEORGE UT
2018-12-17 435-395 0–9 XXXall 10 · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC 6010 HEBER CITY UT
2018-10-19 435-254 0–9 XXXwhole prefix which blocks → ONVOY, LLC - UT 871E PORTAGE UT
2018-10-19 435-266 0–9 XXXall 10 · 2 holders which blocks → ONVOY, LLC - UT 871E LYNNDYL UT
2018-10-19 435-409 2XXX4XXX5XXX8XXX which blocks → ONVOY, LLC - UT 871E SCIPIO UT
2018-10-19 435-422 1XXX2XXX3XXX4XXX6XXX · 3 holders which blocks → ONVOY, LLC - UT 871E HOWELL UT
2018-10-19 435-447 0XXX4XXX7XXX which blocks → ONVOY, LLC - UT 871E FIELDING UT
2018-10-19 435-626 2XXX4XXX6XXX7XXX · 3 holders which blocks → ONVOY, LLC - UT 871E SNOWVILLE UT
2018-10-19 435-923 2XXX3XXX4XXX5XXX which blocks → ONVOY, LLC - UT 871E THATCHER UT
2018-09-28 435-244 0–9 XXXall 10 · 4 holders which blocks → ONVOY, LLC - UT 871E TOOELE UT
2018-04-10 435-466 0–9 XXXall 10 · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - UT 6571 BEARRIV CY UT
2017-11-16 435-522 0–9 XXXall 10 · 7 holders which blocks → CENTURYLINK COMMUNICATIONS, LLC 508J ST GEORGE UT
2017-08-31 435-800 0–9 XXXall 10 · 6 holders which blocks → ONVOY, LLC - UT 871E PARK CITY UT
2017-03-01 435-777 0–9 XXXall 10 · 8 holders which blocks → TELNYX LLC 073H HEBER CITY UT
2016-11-21 435-236 0–9 XXXall 10 · 4 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - UT 6571 ST GEORGE UT
2016-04-28 435-205 none assigned yet which blocks → NEW CINGULAR WIRELESS PCS, LLC 6010 MNZMCRANTH UT

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.