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
2001-05-08 501-566 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 7 holders which blocks → SOUTHWESTERN BELL 9533 JONESMILLS AR
2001-05-08 501-574 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - AR 5179 BENTON AR
2001-03-22 501-772 5XXX7XXX8XXX9XXX which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 LITTLEROCK AR
2001-02-26 501-838 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 LITTLEROCK AR
2001-01-23 501-818 8XXX which blocks → T-MOBILE USA, INC. 6529 MALVERN AR
2001-01-18 501-548 1XXX2XXX4XXX5XXX7XXX8XXX9XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 CONWAY AR
— 501-202 not yet reported which blocks → SOUTHWESTERN BELL 9533 LITTLEROCK AR
— 501-206 1XXX2XXX4XXX which blocks → SOUTHWESTERN BELL 9533 HEBER SPG AR
— 501-207 0XXX8XXX9XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 SEARCY AR
— 501-208 0XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 MORRILTON AR
— 501-210 5XXX8XXX which blocks → SOUTHWESTERN BELL 9533 LITTLEROCK AR
— 501-211 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX AR
— 501-212 not yet reported which blocks → SOUTHWESTERN BELL 9533 LITTLEROCK AR
— 501-217 not yet reported which blocks → SOUTHWESTERN BELL 9533 LITTLEROCK AR
— 501-218 3XXX4XXX5XXX6XXX8XXX9XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 LITTLEROCK AR
— 501-219 not yet reported which blocks → SOUTHWESTERN BELL 9533 LITTLEROCK AR
— 501-220 not yet reported which blocks → WINDSTREAM COMMUNICATIONS, INC. - AR 7656 LITTLEROCK AR
— 501-221 not yet reported which blocks → SOUTHWESTERN BELL 9533 LITTLEROCK AR
— 501-222 1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → WINDSTREAM COMMUNICATIONS, INC. - AR 7656 WRIGHTSVL AR
— 501-223 7XXX which blocks → SOUTHWESTERN BELL 9533 LITTLEROCK AR
— 501-224 not yet reported which blocks → SOUTHWESTERN BELL 9533 LITTLEROCK AR
— 501-225 not yet reported which blocks → SOUTHWESTERN BELL 9533 LITTLEROCK AR
— 501-226 0–9 XXXall 10 · 6 holders which blocks → CSC VOICE, LLC 612K JESSIEVL AR
— 501-227 2XXX which blocks → SOUTHWESTERN BELL 9533 LITTLEROCK AR
— 501-228 not yet reported which blocks → SOUTHWESTERN BELL 9533 LITTLEROCK AR
— 501-230 7XXX8XXX which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 SEARCY AR
— 501-231 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 LITTLEROCK AR
— 501-233 not yet reported which blocks → ARKWEST COMMUNICATIONS, INC. 1734 CASA AR
— 501-235 0XXX3XXX6XXX7XXX8XXX · 3 holders which blocks → AT&T - LOCAL 7421 LITTLEROCK AR
— 501-240 none assigned yet which blocks → T-MOBILE USA, INC. 6529 LITTLEROCK AR
— 501-241 4XXX7XXX · 2 holders which blocks → BRIGHTSPEED OF CENTRAL ARKANSAS, LLC 1144 JACKSONVL AR
— 501-244 3XXX8XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 LITTLEROCK AR
— 501-245 not yet reported which blocks → AMERICAN MESSAGING SERVICES, LLC 9748 LITTLEROCK AR
— 501-247 none assigned yet which blocks → METROPCS, INC. 5562 LITTLEROCK AR
— 501-249 4XXX5XXX7XXX8XXX which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 BENTON AR
— 501-250 1XXX2XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 HEBER SPG AR
— 501-252 not yet reported which blocks → WINDSTREAM COMMUNICATIONS, INC. - AR 7656 LITTLEROCK AR
— 501-255 4XXX8XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - AR 5179 LITTLEROCK AR
— 501-256 0XXX8XXX which blocks → T-MOBILE USA, INC. 6529 LITTLEROCK AR
— 501-257 0XXX7XXX which blocks → SOUTHWESTERN BELL 9533 LITTLEROCK AR
— 501-258 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 LITTLEROCK AR
— 501-259 4XXX7XXX8XXX which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CABOT AR
— 501-260 0–9 XXXall 10 · 5 holders which blocks → T-MOBILE USA, INC. 6529 LITTLEROCK AR
— 501-261 0XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 6 holders which blocks → SOUTHWESTERN BELL 9533 SPRINGLAKE AR
— 501-262 7XXX8XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 HOTSPRINGS AR
— 501-265 9XXX which blocks → SOUTHWESTERN BELL 9533 LITTLEROCK AR
— 501-268 not yet reported which blocks → SOUTHWESTERN BELL 9533 SEARCY AR
— 501-269 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CONWAY AR
— 501-275 not yet reported which blocks → BRIGHTSPEED OF CENTRAL ARKANSAS, LLC 1144 COY AR
— 501-276 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 HOTSPRINGS 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.