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
— 573-563 not yet reported which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MO 7432 FTLENARDWD MO
— 573-564 0XXX4XXX5XXX7XXX9XXX · 5 holders which blocks → SOUTHWESTERN BELL 9533 MONTGORYCY MO
— 573-565 0XXX4XXX5XXX7XXX · 4 holders which blocks → BRIGHTSPEED OF EAST MISSOURI, LLC 1151 PERRY MO
— 573-568 0XXX6XXX7XXX8XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 BLOOMFIELD MO
— 573-570 2XXX3XXX4XXX5XXX · 2 holders which blocks → ONVOY, LLC - MO 093F PERRY MO
— 573-574 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 5 holders which blocks → ONVOY, LLC - MO 093F MONTGORYCY MO
— 573-576 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CAPEGIRARD MO
— 573-578 5XXX7XXX which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 ROLLA MO
— 573-579 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CAPEGIRARD MO
— 573-581 not yet reported which blocks → SOUTHWESTERN BELL 9533 MEXICO MO
— 573-582 9XXX which blocks → SOUTHWESTERN BELL 9533 MEXICO MO
— 573-584 1XXX2XXX4XXX5XXX6XXX7XXX · 4 holders which blocks → EMBARQ MISSOURI, INC. DBA CENTURYLINK - MO 1811 CENTERTOWN MO
— 573-585 0XXX5XXX · 2 holders which blocks → ONVOY, LLC - MO 093F ELLSINORE MO
— 573-587 5XXX7XXX8XXX · 2 holders which blocks → T-MOBILE USA, INC. 6529 CAPEGIRARD MO
— 573-588 6XXX8XXX · 2 holders which blocks → BRIGHTSPEED OF EAST MISSOURI, LLC 1151 SHELBINA MO
— 573-589 0XXX which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 SHELBINA MO
— 573-590 7XXX8XXX9XXX · 3 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MO 5814 FULTON MO
— 573-592 9XXX which blocks → SOUTHWESTERN BELL 9533 FULTON MO
— 573-593 1XXX5XXX8XXX · 3 holders which blocks → WINDSTREAM MISSOURI, INC. 1885 GRANDIN MO
— 573-594 4XXX5XXX8XXX · 2 holders which blocks → WINDSTREAM MISSOURI, INC. 1885 VANDALIA MO
— 573-596 not yet reported which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MO 7432 FTLENARDWD MO
— 573-598 0XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → BRIGHTSPEED OF EAST MISSOURI, LLC 1151 ANNAPOLIS MO
— 573-599 0XXX1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → ONVOY, LLC - MO 093F TUSCUMBIA MO
— 573-609 0–9 XXXall 10 · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 POPLAR BLF MO
— 573-611 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX MO
— 573-614 5XXX7XXX8XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 DEXTER MO
— 573-619 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 JEFFERSNCY MO
— 573-620 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MO 5814 SIKESTON MO
— 573-621 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 7 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MO 5814 SIKESTON MO
— 573-623 0XXX2XXX6XXX7XXX · 3 holders which blocks → ONVOY, LLC - MO 093F OATES MO
— 573-624 not yet reported which blocks → SOUTHWESTERN BELL 9533 DEXTER MO
— 573-626 3XXX6XXX8XXX · 2 holders which blocks → BRIGHTSPEED OF EAST MISSOURI, LLC 1151 BOSS MO
— 573-627 7XXX8XXX which blocks → FIDELITY TELEPHONE, LLC 1882 JAPAN MO
— 573-628 0XXX2XXX6XXX7XXX8XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 WARDELL MO
— 573-631 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 FARMINGTON MO
— 573-632 none assigned yet which blocks → EMBARQ MISSOURI, INC. DBA CENTURYLINK - MO 1811 JEFFERSNCY MO
— 573-633 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → BRIGHTSPEED OF EAST MISSOURI, LLC 1151 SHELBYVL MO
— 573-634 not yet reported which blocks → EMBARQ MISSOURI, INC. DBA CENTURYLINK - MO 1811 JEFFERSNCY MO
— 573-635 not yet reported which blocks → EMBARQ MISSOURI, INC. DBA CENTURYLINK - MO 1811 JEFFERSNCY MO
— 573-636 not yet reported which blocks → EMBARQ MISSOURI, INC. DBA CENTURYLINK - MO 1811 JEFFERSNCY MO
— 573-637 1XXX3XXX4XXX5XXX · 3 holders which blocks → BRIGHTSPEED OF EAST MISSOURI, LLC 1151 LESTERVL MO
— 573-638 8XXX which blocks → EMBARQ MISSOURI, INC. DBA CENTURYLINK - MO 1811 JEFFERSNCY MO
— 573-639 2XXX3XXX4XXX5XXX6XXX7XXX8XXX which blocks → T-MOBILE USA, INC. 6529 COLUMBIA MO
— 573-641 0XXX1XXX2XXX3XXX4XXX8XXX · 4 holders which blocks → BRIGHTSPEED OF MISSOURI, LLC 9784 CLARK MO
— 573-642 not yet reported which blocks → SOUTHWESTERN BELL 9533 FULTON MO
— 573-643 3XXX4XXX5XXX7XXX8XXX · 5 holders which blocks → SOUTHWESTERN BELL 9533 MARSTON MO
— 573-644 0XXX1XXX2XXX3XXX4XXX6XXX7XXX9XXX · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 JEFFERSNCY MO
— 573-645 9XXX which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 JEFFERSNCY MO
— 573-646 0XXX1XXX2XXX4XXX6XXX8XXX9XXX · 4 holders which blocks → BRIGHTSPEED OF MISSOURI, LLC 9787 BLAND MO
— 573-647 2XXX3XXX4XXX7XXX · 2 holders which blocks → T-MOBILE USA, INC. 6529 ROLLA 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.