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
— 573-219 3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → T-MOBILE USA, INC. 6529 COLUMBIA MO
— 573-220 8XXX which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 FULTON MO
— 573-221 not yet reported which blocks → SOUTHWESTERN BELL 9533 HANNIBAL MO
— 573-222 0XXX4XXX5XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 PUXICO MO
— 573-223 5XXX8XXX · 2 holders which blocks → WINDSTREAM MISSOURI, INC. 1885 PIEDMONT MO
— 573-224 1XXX2XXX4XXX8XXX · 2 holders which blocks → WINDSTREAM MISSOURI, INC. 1885 GREENVILLE MO
— 573-225 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CAPEGIRARD MO
— 573-226 0XXX2XXX4XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → BRIGHTSPEED OF EAST MISSOURI, LLC 1151 EMINENCE MO
— 573-228 5XXX6XXX8XXX9XXX · 3 holders which blocks → UNITED STATES CELLULAR - MO 6275 COLUMBIA MO
— 573-229 0XXX2XXX3XXX5XXX6XXX8XXX9XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 META MO
— 573-230 0XXX which blocks → T-MOBILE USA, INC. 6529 JEFFERSNCY MO
— 573-231 4XXX7XXX8XXX9XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 HANNIBAL MO
— 573-234 0XXX3XXX4XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → BRIGHTSPEED OF MISSOURI, LLC 9784 COLUMBIA MO
— 573-236 none assigned yet which blocks → KINGDOM TEL. CO. 1901 RHINELAND MO
— 573-237 7XXX8XXX · 2 holders which blocks → FIDELITY TELEPHONE, LLC 1882 NEW HAVEN MO
— 573-238 6XXX7XXX8XXX9XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 MARBLEHILL MO
— 573-239 4XXX5XXX6XXX7XXX8XXX9XXX which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 COLUMBIA MO
— 573-241 2XXX3XXX4XXX8XXX9XXX · 3 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MO 5814 CUBA MO
— 573-242 0XXX2XXX4XXX5XXX6XXX8XXX · 5 holders which blocks → SOUTHWESTERN BELL 9533 CLARKSVL MO
— 573-243 not yet reported which blocks → SOUTHWESTERN BELL 9533 JACKSON MO
— 573-244 not yet reported which blocks → STEELVILLE TEL. EXCH., INC. 1949 VIBURNUM MO
— 573-245 0XXX1XXX2XXX3XXX4XXX5XXX8XXX9XXX · 3 holders which blocks → BRIGHTSPEED OF MISSOURI, LLC 9787 LEASBURG MO
— 573-246 0XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → SOUTHWESTERN BELL 9533 CAMPBELL MO
— 573-247 4XXX5XXX8XXX9XXX which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 SALEM MO
— 573-248 none assigned yet which blocks → SOUTHWESTERN BELL 9533 HANNIBAL MO
— 573-249 none assigned yet which blocks → FARBER TEL. CO. 1876 FARBER MO
— 573-251 0XXX1XXX2XXX5XXX7XXX · 4 holders which blocks → BRIGHTSPEED OF EAST MISSOURI, LLC 1151 FREMONT MO
— 573-252 none assigned yet which blocks → KINGDOM TEL. CO. 1901 BIGSPRING MO
— 573-254 none assigned yet which blocks → KINGDOM TEL. CO. 1901 WILLIAMSBG MO
— 573-255 0XXX1XXX2XXX4XXX5XXX6XXX8XXX9XXX · 5 holders which blocks → WINDSTREAM MISSOURI, INC. 1885 PONDER MO
— 573-256 9XXX which blocks → BRIGHTSPEED OF MISSOURI, LLC 9784 COLUMBIA MO
— 573-257 2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → ONVOY SPECTRUM, LLC 624H JEFFERSNCY MO
— 573-258 3XXX4XXX5XXX8XXX · 3 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 SIKESTON MO
— 573-259 4XXX5XXX6XXX which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 CUBA MO
— 573-261 3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MO 5814 ST JAMES MO
— 573-262 0XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → SOUTHWESTERN BELL 9533 ORAN MO
— 573-263 2XXX4XXX5XXX6XXX7XXX9XXX · 2 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 ST JAMES MO
— 573-264 0XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 SCOTT CITY MO
— 573-265 9XXX which blocks → BRIGHTSPEED OF MISSOURI, LLC 9787 ST JAMES MO
— 573-266 0XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → SOUTHWESTERN BELL 9533 OAK RIDGE MO
— 573-267 0XXX2XXX4XXX5XXX6XXX8XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 CENTER MO
— 573-268 none assigned yet which blocks → T-MOBILE USA, INC. 6529 COLUMBIA MO
— 573-269 0XXX2XXX3XXX5XXX9XXX · 4 holders which blocks → BRIGHTSPEED OF EAST MISSOURI, LLC 1151 OATES MO
— 573-270 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MO 5814 CAPEGIRARD MO
— 573-271 2XXX3XXX5XXX7XXX8XXX9XXX · 6 holders which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MO 5814 CAPEGIRARD MO
— 573-272 not yet reported which blocks → AMERICAN MESSAGING SERVICES, LLC 9748 SIKESTON MO
— 573-276 0XXX9XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 MALDEN MO
— 573-278 not yet reported which blocks → AMERICAN MESSAGING SERVICES, LLC 9748 CAPEGIRARD MO
— 573-280 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 LKOZKOSBCH MO
— 573-283 0XXX2XXX3XXX4XXX6XXX7XXX8XXX · 5 holders which blocks → SOUTHWESTERN BELL 9533 ESSEX 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.