NumberResearch Membership · Data 09/20/2026

Recent prefix assignments

0 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/20/2026

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 501
SOUTHWESTERN BELL 165
NEW CINGULAR WIRELESS PCS, LLC - IL 86
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AR 54
LEVEL 3 COMMUNICATIONS, LLC - AR 48
T-MOBILE USA, INC. 42
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
2003-07-23 501-633 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - AR 5179 LITTLEROCK AR
2003-07-23 501-634 0XXX which blocks → LEVEL 3 COMMUNICATIONS, LLC - AR 5179 LITTLEROCK AR
2003-07-23 501-635 5XXX9XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - AR 5179 LITTLEROCK AR
2003-07-23 501-636 8XXX which blocks → LEVEL 3 COMMUNICATIONS, LLC - AR 5179 LITTLEROCK AR
2003-07-23 501-637 8XXX which blocks → LEVEL 3 COMMUNICATIONS, LLC - AR 5179 LITTLEROCK AR
2003-07-23 501-638 8XXX which blocks → LEVEL 3 COMMUNICATIONS, LLC - AR 5179 LITTLEROCK AR
2003-07-23 501-639 8XXX which blocks → LEVEL 3 COMMUNICATIONS, LLC - AR 5179 LITTLEROCK AR
2003-04-29 501-266 0–9 XXXall 10 · 5 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AR 6805 LONOKE AR
2003-04-28 501-215 1XXX2XXX3XXX4XXX5XXX6XXX8XXX · 5 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 MORRILTON AR
2003-04-23 501-238 1XXX3XXX4XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AR 6805 GREERSFRRY AR
2003-04-23 501-239 2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AR 6805 BEEBE AR
2003-03-18 501-229 0–9 XXXall 10 · 6 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - AR 5179 MALVERN AR
2003-03-12 501-213 0XXX1XXX2XXX3XXX4XXX · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 BRYANTCGVL AR
2003-03-10 501-209 3XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AR 6805 JESSIEVL AR
2002-12-31 501-277 1XXX2XXX3XXX5XXX6XXX · 3 holders which blocks → T-MOBILE USA, INC. 6529 GREENBRIER AR
2002-12-23 501-205 2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - AR 5179 CONWAY AR
2002-11-22 501-204 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → METROPCS, INC. 5562 JESSIEVL AR
2002-11-20 501-203 0–9 XXXall 10 · 9 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AR 6805 SEARCY AR
2002-10-17 501-200 0XXX1XXX3XXX4XXX5XXX6XXX8XXX9XXX · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 REDFIELD AR
2002-10-17 501-201 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 BRADFORD AR
2002-10-16 501-283 7XXX8XXX · 2 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 BALD KNOB AR
2002-10-16 501-284 5XXX6XXX7XXX8XXX · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 JUDSONIA AR
2002-10-16 501-285 1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 ENGLAND AR
2002-07-15 501-593 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX which blocks → LEVEL 3 COMMUNICATIONS, LLC - AR 5179 SEARCY AR
2002-06-20 501-499 5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CONWAY AR
2002-06-19 501-242 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - AR 5179 MORRILTON AR
2002-06-14 501-545 2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 HOTSPRINGS AR
2002-05-13 501-458 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - AR 5179 MALVERN AR
2002-05-13 501-881 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - AR 5179 HOTSPRINGS AR
2002-05-06 501-429 0XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - AR 5179 HEBER SPG AR
2002-05-06 501-436 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - AR 5179 SYVNHLSHWD AR
2002-05-06 501-438 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 7 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - AR 5179 LONOKE AR
2002-05-06 501-550 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - AR 5179 GREERSFRRY AR
2002-05-06 501-588 0XXX1XXX2XXX3XXX7XXX8XXX9XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - AR 5179 LITTLEROCK AR
2002-04-09 501-428 6XXX7XXX which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AR 6805 CONWAY AR
2002-04-08 501-270 3XXX4XXX6XXX7XXX8XXX · 2 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AR 6805 HEBER SPG AR
2002-04-08 501-304 4XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AR 6805 MALVERN AR
2002-04-08 501-326 0XXX6XXX7XXX8XXX · 3 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AR 6805 BENTON AR
2002-02-15 501-398 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 LITTLEROCK AR
2002-01-09 501-744 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 LITTLEROCK AR
2001-12-27 501-533 0XXX3XXX4XXX5XXX7XXX8XXX9XXX · 2 holders which blocks → BRIGHTSPEED OF CENTRAL ARKANSAS, LLC 1144 JACKSONVL AR
2001-12-05 501-447 not yet reported which blocks → WINDSTREAM COMMUNICATIONS, INC. - AR 7656 LITTLEROCK AR
2001-11-07 501-552 not yet reported which blocks → WINDSTREAM COMMUNICATIONS, INC. - AR 7656 LITTLEROCK AR
2001-08-20 501-473 2XXX3XXX4XXX5XXX which blocks → T-MOBILE USA, INC. 6529 SEARCY AR
2001-07-18 501-773 3XXX which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 LITTLEROCK AR
2001-07-05 501-817 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX9XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - AR 5179 FERNDALE AR
2001-06-25 501-391 1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → WINDSTREAM ARKANSAS, INC. 1691 PERRYVILLE AR
2001-05-08 501-339 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CONWAY AR
2001-05-08 501-365 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 7 holders which blocks → SOUTHWESTERN BELL 9533 HEBER SPG AR
2001-05-08 501-386 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - AR 5179 CENTER RDG AR

Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/20/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.