NumberResearchRecent prefix assignments
0 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/20/2026
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
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| Assigned | NPA-NXX | Thousands-blocks taken (last-4 opening) | Code holder | OCN | Rate center | State |
|---|---|---|---|---|---|---|
| 2017-11-02 | 573-506 | 0XXX2XXX · 2 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | TEBBETTS | MO |
| 2017-11-02 | 573-597 | 2XXX5XXX9XXX · 3 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | AUXVASSE | MO |
| 2017-11-02 | 573-716 | 2XXX which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | WILLIAMSBG | MO |
| 2017-11-02 | 573-809 | 2XXX6XXX · 2 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | MOKANE | MO |
| 2017-11-02 | 573-839 | 2XXX which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | RHINELAND | MO |
| 2017-11-02 | 573-912 | 2XXX which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | HATTON | MO |
| 2017-11-02 | 573-977 | 2XXX7XXX9XXX · 3 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | BIGSPRING | MO |
| 2017-02-27 | 573-520 | 0–9 XXXall 10 · 6 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | RUSSELLVL | MO |
| 2016-07-28 | 573-963 | 0XXX1XXX2XXX3XXX4XXX5XXX7XXX8XXX · 6 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | NEW MADRID | MO |
| 2014-09-01 | 573-607 | 0–9 XXXall 10 · 4 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | COLUMBIA | MO |
| 2013-08-13 | 573-412 | 0–9 XXXall 10 · 6 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | PORTAGEVL | MO |
| 2007-01-08 | 573-625 | 0–9 XXXall 10 · 4 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | DEXTER | MO |
| 2006-05-09 | 573-503 | 0XXX1XXX4XXX8XXX · 4 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | MIDDLETOWN | MO |
| 2006-05-09 | 573-662 | 2XXX4XXX · 2 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | IBERIA | MO |
| 2006-05-09 | 573-710 | 0XXX4XXX5XXX7XXX8XXX · 4 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | MARTINSBG | MO |
| 2006-05-09 | 573-844 | 4XXX8XXX · 2 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | CROCKER | MO |
| 2006-05-09 | 573-917 | 0XXX4XXX5XXX · 2 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | DIXON | MO |
| 2006-04-28 | 573-828 | 0XXX1XXX2XXX4XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | VANDALIA | MO |
| 2005-12-12 | 573-995 | 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 4 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | BELLFLOWER | MO |
| 2005-08-03 | 573-830 | 0XXX1XXX4XXX · 3 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | NEELYVILLE | MO |
| 2005-02-11 | 573-750 | 7XXX which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | EUGENE | MO |
| 2004-12-30 | 573-464 | 3XXX6XXX7XXX · 2 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | CALIFORNIA | MO |
| 2004-12-30 | 573-622 | 0XXX which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | CLARKSBURG | MO |
| 2004-04-06 | 573-417 | 1XXX2XXX3XXX6XXX8XXX9XXX · 5 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | LINN | MO |
| 2003-11-04 | 573-285 | 1XXX2XXX8XXX · 3 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | CLARKSBURG | MO |
| 2003-01-10 | 573-312 | 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 6 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | ELSBERRY | MO |
| 2003-01-10 | 573-314 | 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | FRANKFORD | MO |
| 2003-01-10 | 573-319 | 0–9 XXXall 10 · 4 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | MACKSCREEK | MO |
| 2003-01-10 | 573-321 | 0XXX1XXX2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 5 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | ADVANCE | MO |
| 2003-01-10 | 573-340 | 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 4 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | WELLSVILLE | MO |
| 2003-01-10 | 573-342 | 0–9 XXXall 10 · 4 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | RICHWOODS | MO |
| 2003-01-10 | 573-349 | 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 6 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | PATTON | MO |
| 2003-01-10 | 573-352 | 0–9 XXXall 10 · 6 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | POCAHONTAS | MO |
| 2003-01-09 | 573-206 | 0XXX1XXX2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | BEAUFORT | MO |
| 2003-01-09 | 573-207 | 0–9 XXXall 10 · 6 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | GRAVOIS ML | MO |
| 2003-01-09 | 573-208 | 0–9 XXXall 10 · 4 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | MARBLEHILL | MO |
| 2003-01-09 | 573-213 | 0–9 XXXall 10 · 9 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | BOWLNGGREN | MO |
| 2003-01-09 | 573-217 | 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | CAMPBELL | MO |
| 2003-01-09 | 573-240 | 0–9 XXXall 10 · 6 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | CENTER | MO |
| 2003-01-09 | 573-250 | 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | CLARKSVL | MO |
| 2003-01-09 | 573-260 | 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 5 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | CLIMAX SPG | MO |
| 2003-01-06 | 573-203 | 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | SENATH | MO |
| 2002-08-09 | 573-595 | 2XXX5XXX7XXX8XXX · 3 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | EUGENE | MO |
| 2002-06-04 | 573-433 | 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 3 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | WAYNESVL | MO |
| 2002-05-15 | 573-287 | 0XXX1XXX · 2 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | PIEDMONT | MO |
| 2002-05-07 | 573-557 | 0–9 XXXall 10 · 8 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | ELDON | MO |
| 2002-05-07 | 573-559 | 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 4 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | KENNETT | MO |
| 2002-05-07 | 573-560 | 0–9 XXXall 10 · 8 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | LOUISIANA | MO |
| 2002-05-07 | 573-567 | 0–9 XXXall 10 · 8 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | MEXICO | MO |
| 2002-05-07 | 573-569 | 0–9 XXXall 10 · 4 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MO | 4932 | VERSAILLES | 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.