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
— 573-474 not yet reported which blocks → BRIGHTSPEED OF MISSOURI, LLC 9784 COLUMBIA MO
— 573-475 0XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → SOUTHWESTERN BELL 9533 SIKESTON MO
— 573-477 5XXX6XXX · 2 holders which blocks → EMBARQ MISSOURI, INC. DBA CENTURYLINK - MO 1811 ST THOMAS MO
— 573-478 not yet reported which blocks → MARK TWAIN RURAL TEL. CO. 1914 DURHAM MO
— 573-480 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 LKOZKOSBCH MO
— 573-481 2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 SIKESTON MO
— 573-482 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 FARMINGTON MO
— 573-483 0XXX4XXX5XXX6XXX8XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 BLOOMSDALE MO
— 573-484 2XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → SOUTHWESTERN BELL 9533 BEAUFORT MO
— 573-485 1XXX5XXX · 2 holders which blocks → WINDSTREAM MISSOURI, INC. 1885 EOLIA MO
— 573-486 4XXX6XXX · 2 holders which blocks → BRIGHTSPEED OF MISSOURI, LLC 9785 HERMANN MO
— 573-487 0XXX1XXX3XXX4XXX7XXX · 4 holders which blocks → ONVOY, LLC - MO 093F LESTERVL MO
— 573-489 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 COLUMBIA MO
— 573-490 0XXX2XXX3XXX4XXX7XXX · 3 holders which blocks → ONVOY, LLC - MO 093F LEWISTOWN MO
— 573-491 1XXX5XXX6XXX · 3 holders which blocks → EMBARQ MISSOURI, INC. DBA CENTURYLINK - MO 1811 NEWBLOMFLD MO
— 573-492 1XXX2XXX3XXX4XXX7XXX · 4 holders which blocks → WINDSTREAM MISSOURI, INC. 1885 MARTINSBG MO
— 573-493 3XXX4XXX5XXX6XXX8XXX · 2 holders which blocks → WINDSTREAM MISSOURI, INC. 1885 STELIZABTH MO
— 573-494 2XXX4XXX5XXX6XXX7XXX9XXX · 5 holders which blocks → BRIGHTSPEED OF EAST MISSOURI, LLC 1151 EWING MO
— 573-495 1XXX3XXX4XXX5XXX · 4 holders which blocks → WINDSTREAM MISSOURI, INC. 1885 CLUBB MO
— 573-496 1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → EMBARQ MISSOURI, INC. DBA CENTURYLINK - MO 1811 BRAZITO MO
— 573-497 3XXX which blocks → BRIGHTSPEED OF EAST MISSOURI, LLC 1151 LEWISTOWN MO
— 573-498 1XXX2XXX4XXX8XXX · 2 holders which blocks → EMBARQ MISSOURI, INC. DBA CENTURYLINK - MO 1811 EUGENE MO
— 573-499 not yet reported which blocks → BRIGHTSPEED OF MISSOURI, LLC 9784 COLUMBIA MO
— 573-511 not yet reported which blocks → MULTIPLE OCN LISTING MULT XXXXXXXXXX MO
— 573-512 2XXX3XXX5XXX · 3 holders which blocks → T-MOBILE USA, INC. 6529 FTLENARDWD MO
— 573-513 8XXX which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MO 5814 PERRYVILLE MO
— 573-514 0–9 XXXall 10 · 6 holders which blocks → T-MOBILE USA, INC. 6529 COLUMBIA MO
— 573-515 0XXX1XXX2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 6 holders which blocks → ONVOY, LLC - MO 093F SHELBINA MO
— 573-517 4XXX6XXX8XXX9XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 PERRYVILLE MO
— 573-518 5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 FLAT RIVER MO
— 573-519 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → SOUTHWESTERN BELL 9533 CAPEGIRARD MO
— 573-521 1XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 NEW MADRID MO
— 573-522 not yet reported which blocks → EMBARQ MISSOURI, INC. DBA CENTURYLINK - MO 1811 JEFFERSNCY MO
— 573-526 not yet reported which blocks → EMBARQ MISSOURI, INC. DBA CENTURYLINK - MO 1811 JEFFERSNCY MO
— 573-528 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 WAYNESVL MO
— 573-529 2XXX4XXX5XXX7XXX8XXX which blocks → T-MOBILE USA, INC. 6529 COLUMBIA MO
— 573-531 0XXX2XXX3XXX4XXX5XXX7XXX8XXX · 4 holders which blocks → ONVOY, LLC - MO 093F TIMBER MO
— 573-537 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 ROLLA MO
— 573-538 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → ONVOY, LLC - MO 093F BOSS MO
— 573-543 0XXX6XXX7XXX9XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 ST MARYS MO
— 573-545 0XXX2XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → SOUTHWESTERN BELL 9533 BENTON MO
— 573-546 9XXX which blocks → BRIGHTSPEED OF EAST MISSOURI, LLC 1151 IRONTON MO
— 573-547 0XXX which blocks → SOUTHWESTERN BELL 9533 PERRYVILLE MO
— 573-548 0XXX1XXX4XXX5XXX · 3 holders which blocks → BRIGHTSPEED OF EAST MISSOURI, LLC 1151 MONTAUK MO
— 573-549 3XXX4XXX7XXX8XXX which blocks → WINDSTREAM MISSOURI, INC. 1885 MIDDLETOWN MO
— 573-551 0–9 XXXall 10 · 7 holders which blocks → ONVOY, LLC - MO 093F KENNETT MO
— 573-555 not yet reported which blocks → MULTIPLE OCN LISTING MULT DIR ASST MO
— 573-556 not yet reported which blocks → EMBARQ MISSOURI, INC. DBA CENTURYLINK - MO 1811 JEFFERSNCY MO
— 573-558 not yet reported which blocks → ELLINGTON TEL. CO. 1874 REDFORD MO
— 573-562 0XXX3XXX5XXX6XXX8XXX · 5 holders which blocks → SOUTHWESTERN BELL 9533 LEADWOOD 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.