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 520
QWEST CORPORATION 201
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AZ 104
T-MOBILE USA, INC. 84
NEW CINGULAR WIRELESS PCS, LLC 53
ONVOY, LLC - AZ 47
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
— 520-847 not yet reported which blocks → VALLEY TEL COOP INC 2176 BOWIE AZ
— 520-850 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AZ 6572 TUCSON AZ
— 520-860 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AZ 6572 NOGALES AZ
— 520-861 none assigned yet which blocks → T-MOBILE USA, INC. 6529 TUCSON AZ
— 520-868 not yet reported which blocks → QWEST CORPORATION 9636 CASAGRANDE AZ
— 520-869 none assigned yet which blocks → T-MOBILE USA, INC. 6529 TUCSON AZ
— 520-870 none assigned yet which blocks → T-MOBILE USA, INC. 6529 TUCSON AZ
— 520-872 not yet reported which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-873 7XXX8XXX9XXX · 3 holders which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-874 0–9 XXXwhole prefix which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-876 not yet reported which blocks → QWEST CORPORATION 9636 CASAGRANDE AZ
— 520-877 none assigned yet which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-878 3XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-879 not yet reported which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-880 not yet reported which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-881 not yet reported which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-882 not yet reported which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-883 not yet reported which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-884 none assigned yet which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-885 not yet reported which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-886 not yet reported which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-887 not yet reported which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-888 not yet reported which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-889 not yet reported which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-891 not yet reported which blocks → T-MOBILE USA, INC. 6529 TUCSON AZ
— 520-895 0XXX1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 7 holders which blocks → LEVEL 3 TELECOM OF ARIZONA, LLC - AZ 7552 SIERRAVIST AZ
— 520-896 1XXX4XXX5XXX7XXX8XXX · 3 holders which blocks → QWEST CORPORATION 9636 SAN MANUEL AZ
— 520-901 0XXX which blocks → LEVEL 3 TELECOM OF ARIZONA, LLC - AZ 7552 TUCSON AZ
— 520-903 4XXX7XXX8XXX which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-904 4XXX6XXX7XXX8XXX9XXX which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AZ 6572 TUCSON AZ
— 520-906 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC 6010 TUCSON AZ
— 520-907 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC 6010 TUCSON AZ
— 520-908 6XXX7XXX which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-909 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AZ 6572 TUCSON AZ
— 520-911 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX AZ
— 520-917 not yet reported which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - AZ 7465 TUCSON AZ
— 520-918 not yet reported which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - AZ 7465 TUCSON AZ
— 520-921 none assigned yet which blocks → T-MOBILE USA, INC. 6529 SEDONA AZ
— 520-924 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → ELECTRIC LIGHTWAVE LLC DBA ALLSTREAM 7175 NOGALES AZ
— 520-940 9XXX which blocks → T-MOBILE USA, INC. 6529 TUCSON AZ
— 520-950 not yet reported which blocks → AZ
— 520-954 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AZ 6572 TUCSON AZ
— 520-955 5XXX6XXX8XXX9XXX which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AZ 6572 TUCSON AZ
— 520-958 not yet reported which blocks → AZ
— 520-959 not yet reported which blocks → AZ
— 520-971 0XXX which blocks → T-MOBILE USA, INC. 6529 TUCSON AZ
— 520-975 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AZ 6572 TUCSON AZ
— 520-976 not yet reported which blocks → AZ
— 520-977 none assigned yet which blocks → T-MOBILE USA, INC. 6529 TUCSON AZ
— 520-979 3XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → T-MOBILE USA, INC. 6529 TUCSON 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.