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 573
SOUTHWESTERN BELL 128
NEW CINGULAR WIRELESS PCS, LLC - IL 113
ONVOY, LLC - MO 86
LEVEL 3 COMMUNICATIONS, LLC - MO 63
T-MOBILE USA, INC. 44
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
— 573-785 not yet reported which blocks → SOUTHWESTERN BELL 9533 POPLAR BLF MO
— 573-786 not yet reported which blocks → STEELVILLE TEL. EXCH., INC. 1949 HUZZAH MO
— 573-787 4XXX5XXX7XXX8XXX which blocks → EMBARQ MISSOURI, INC. DBA CENTURYLINK - MO 1811 CLARKSBURG MO
— 573-788 0XXX3XXX4XXX5XXX6XXX8XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 OLDAPPLETN MO
— 573-789 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → UNITED STATES CELLULAR - MO 6275 VERSAILLES MO
— 573-791 0XXX2XXX3XXX7XXX · 3 holders which blocks → ONVOY, LLC - MO 093F EDGAR SPG MO
— 573-792 0XXX2XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 HOLCOMB MO
— 573-793 none assigned yet which blocks → WINDSTREAM MISSOURI, INC. 1885 IBERIA MO
— 573-794 3XXX4XXX5XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 DELTA MO
— 573-795 8XXX which blocks → T-MOBILE USA, INC. 6529 HANNIBAL MO
— 573-796 not yet reported which blocks → EMBARQ MISSOURI, INC. DBA CENTURYLINK - MO 1811 CALIFORNIA MO
— 573-797 3XXX4XXX5XXX8XXX which blocks → T-MOBILE USA, INC. 6529 JEFFERSNCY MO
— 573-799 0XXX1XXX2XXX3XXX7XXX8XXX · 5 holders which blocks → VONAGE AMERICA LLC 197D LINN MO
— 573-808 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 COLUMBIA MO
— 573-811 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX MO
— 573-814 8XXX9XXX · 2 holders which blocks → BRIGHTSPEED OF MISSOURI, LLC 9784 COLUMBIA MO
— 573-815 not yet reported which blocks → BRIGHTSPEED OF MISSOURI, LLC 9784 COLUMBIA MO
— 573-817 not yet reported which blocks → BRIGHTSPEED OF MISSOURI, LLC 9784 COLUMBIA MO
— 573-818 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX9XXX · 7 holders which blocks → UNITED STATES CELLULAR - MO 6275 COLUMBIA MO
— 573-819 none assigned yet which blocks → UNITED STATES CELLULAR - MO 6275 COLUMBIA MO
— 573-820 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MO 5814 DEXTER MO
— 573-821 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 JEFFERSNCY MO
— 573-822 none assigned yet which blocks → UNITED STATES CELLULAR - MO 6275 HANNIBAL MO
— 573-824 0XXX2XXX3XXX4XXX7XXX8XXX9XXX · 6 holders which blocks → SOUTHWESTERN BELL 9533 ALTEBGFRHN MO
— 573-825 0–9 XXXwhole prefix which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 COLUMBIA MO
— 573-832 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → T-MOBILE USA, INC. 6529 VERSAILLES MO
— 573-833 0XXX3XXX4XXX5XXX8XXX9XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 POCAHONTAS MO
— 573-834 3XXX which blocks → FIDELITY TELEPHONE, LLC 1882 BERGER MO
— 573-835 5XXX6XXX · 2 holders which blocks → NEW FLORENCE TEL. CO., INC. 1927 NEWFLORNCE MO
— 573-836 2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CAMDENTON MO
— 573-840 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 7 holders which blocks → SOUTHWESTERN BELL 9533 POPLAR BLF MO
— 573-847 0XXX3XXX4XXX5XXX8XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 PAYNESVL MO
— 573-848 4XXX8XXX · 2 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MO 4932 STEELE MO
— 573-851 1XXX9XXX · 2 holders which blocks → BANDWIDTH.COM CLEC, LLC - MO 993E SALEM MO
— 573-853 not yet reported which blocks → MARK TWAIN RURAL TEL. CO. 1914 WILLIAMSTN MO
— 573-856 1XXX3XXX5XXX9XXX · 4 holders which blocks → WINDSTREAM MISSOURI, INC. 1885 PATTERSON MO
— 573-857 4XXX5XXX8XXX · 3 holders which blocks → WINDSTREAM MISSOURI, INC. 1885 FAIRDEALNG MO
— 573-858 8XXX9XXX which blocks → BRIGHTSPEED OF EAST MISSOURI, LLC 1151 TIMBER MO
— 573-859 0XXX1XXX2XXX4XXX5XXX8XXX9XXX · 4 holders which blocks → BRIGHTSPEED OF MISSOURI, LLC 9785 BELLE MO
— 573-860 0XXX8XXX9XXX which blocks → FIDELITY TELEPHONE, LLC 1882 SULLIVAN MO
— 573-863 2XXX3XXX which blocks → ONVOY, LLC - MO 093F CALIFORNIA MO
— 573-864 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 COLUMBIA MO
— 573-866 0XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → SOUTHWESTERN BELL 9533 PATTON MO
— 573-872 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → T-MOBILE USA, INC. 6529 POPLAR BLF MO
— 573-873 0XXX2XXX4XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → SOUTHWESTERN BELL 9533 CAMDENTON MO
— 573-874 not yet reported which blocks → BRIGHTSPEED OF MISSOURI, LLC 9784 COLUMBIA MO
— 573-875 not yet reported which blocks → BRIGHTSPEED OF MISSOURI, LLC 9784 COLUMBIA MO
— 573-876 not yet reported which blocks → BRIGHTSPEED OF MISSOURI, LLC 9784 COLUMBIA MO
— 573-879 2XXX3XXX8XXX which blocks → ONVOY, LLC - MO 093F LADDONIA MO
— 573-880 2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MO 5814 STEGNVIEVE MO

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.