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
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Recent NPA-NXX prefix assignments
AssignedNPA-NXXThousands-blocks taken (last-4 opening)Code holderOCNRate centerState
— 520-594 0XXX1XXX3XXX8XXX · 3 holders which blocks → WAVENATION, LLC 700J TUCSON AZ
— 520-603 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AZ 6572 TUCSON AZ
— 520-604 3XXX4XXX5XXX9XXX · 2 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AZ 6572 NOGALES AZ
— 520-609 3XXX4XXX5XXX6XXX7XXX8XXX9XXX which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AZ 6572 TUCSON AZ
— 520-610 3XXX4XXX5XXX6XXX7XXX8XXX which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AZ 6572 SACATON AZ
— 520-611 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX AZ
— 520-615 not yet reported which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-616 2XXX which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-617 not yet reported which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-618 9XXX which blocks → LEVEL 3 TELECOM OF ARIZONA, LLC - AZ 7552 TUCSON AZ
— 520-620 not yet reported which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-621 not yet reported which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-622 not yet reported which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-623 not yet reported which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-624 not yet reported which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-625 not yet reported which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-626 not yet reported which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-628 0XXX which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-629 not yet reported which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-631 none assigned yet which blocks → T-MOBILE USA, INC. 6529 TUCSON AZ
— 520-642 not yet reported which blocks → VALLEY TEL COOP INC 2176 ELFRIDA AZ
— 520-647 1XXX2XXX4XXX5XXX6XXX8XXX9XXX · 5 holders which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-648 not yet reported which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-661 0XXX which blocks → T-MOBILE USA, INC. 6529 TUCSON AZ
— 520-663 not yet reported which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-664 3XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-665 1XXX8XXX9XXX which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-670 not yet reported which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-678 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AZ 6572 SIERRAVIST AZ
— 520-682 not yet reported which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-685 0–9 XXXall 10 · 4 holders which blocks → COMCAST IP PHONE, LLC 318J SIERRAVIST AZ
— 520-689 4XXX6XXX7XXX8XXX · 2 holders which blocks → QWEST CORPORATION 9636 SUPERIOR AZ
— 520-690 not yet reported which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-694 not yet reported which blocks → LEVEL 3 TELECOM OF ARIZONA, LLC - AZ 7552 TUCSON AZ
— 520-695 not yet reported which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-696 not yet reported which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-700 not yet reported which blocks → AZ
— 520-705 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AZ 6572 CASAGRANDE AZ
— 520-709 3XXX4XXX5XXX6XXX7XXX8XXX9XXX which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AZ 6572 CASAGRANDE AZ
— 520-711 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX AZ
— 520-712 not yet reported which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-720 0XXX1XXX3XXX6XXX7XXX8XXX · 5 holders which blocks → QWEST CORPORATION 9636 BENSON AZ
— 520-721 not yet reported which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-722 not yet reported which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-723 not yet reported which blocks → QWEST CORPORATION 9636 CASAGRANDE AZ
— 520-730 2XXX3XXX6XXX which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AZ 6572 TUCSON AZ
— 520-731 not yet reported which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-733 not yet reported which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-740 not yet reported which blocks → QWEST CORPORATION 9636 TUCSON AZ
— 520-741 not yet reported which blocks → QWEST CORPORATION 9636 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.