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 314
SOUTHWESTERN BELL 255
NEW CINGULAR WIRELESS PCS, LLC - IL 101
T-MOBILE USA, INC. 94
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MO 53
MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MO 51
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
— 314-523 not yet reported which blocks → SOUTHWESTERN BELL 9533 CREVECOEUR MO
— 314-524 not yet reported which blocks → SOUTHWESTERN BELL 9533 LADUE MO
— 314-525 5XXX which blocks → SOUTHWESTERN BELL 9533 SAPPINGTON MO
— 314-527 0XXX1XXX2XXX3XXX4XXX9XXX · 2 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MO 7432 LADUE MO
— 314-529 0XXX1XXX3XXX4XXX5XXX7XXX8XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 CREVECOEUR MO
— 314-531 not yet reported which blocks → SOUTHWESTERN BELL 9533 ST LOUIS MO
— 314-533 not yet reported which blocks → SOUTHWESTERN BELL 9533 ST LOUIS MO
— 314-534 8XXX which blocks → SOUTHWESTERN BELL 9533 ST LOUIS MO
— 314-535 not yet reported which blocks → SOUTHWESTERN BELL 9533 ST LOUIS MO
— 314-537 not yet reported which blocks → T-MOBILE USA, INC. 6529 ST LOUIS MO
— 314-538 not yet reported which blocks → SOUTHWESTERN BELL 9533 LADUE MO
— 314-539 1XXX which blocks → SOUTHWESTERN BELL 9533 ST LOUIS MO
— 314-540 8XXX9XXX which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 KIRKWOOD MO
— 314-541 8XXX9XXX which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 KIRKWOOD MO
— 314-542 8XXX which blocks → SOUTHWESTERN BELL 9533 CREVECOEUR MO
— 314-543 not yet reported which blocks → SOUTHWESTERN BELL 9533 SAPPINGTON MO
— 314-544 not yet reported which blocks → SOUTHWESTERN BELL 9533 ST LOUIS MO
— 314-545 not yet reported which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - MO 7218 LADUE MO
— 314-548 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → AT&T - LOCAL 7421 CREVECOEUR MO
— 314-549 0–9 XXXall 10 · 3 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MO 4932 OAKVILLE MO
— 314-550 8XXX9XXX which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 KIRKWOOD MO
— 314-551 2XXX6XXX7XXX9XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 LADUE MO
— 314-552 1XXX which blocks → SOUTHWESTERN BELL 9533 ST LOUIS MO
— 314-553 9XXX which blocks → SOUTHWESTERN BELL 9533 ST LOUIS MO
— 314-554 not yet reported which blocks → SOUTHWESTERN BELL 9533 ST LOUIS MO
— 314-555 not yet reported which blocks → MULTIPLE OCN LISTING MULT DIR ASST MO
— 314-558 3XXX7XXX8XXX which blocks → LEVEL 3 COMMUNICATIONS, LLC - MO 4932 ST LOUIS MO
— 314-559 not yet reported which blocks → AMERICAN MESSAGING SERVICES, LLC 9748 ST LOUIS MO
— 314-560 8XXX9XXX which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 KIRKWOOD MO
— 314-562 0–9 XXXall 10 · 2 holders which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 LADUE MO
— 314-563 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → LEVEL 3 COMMUNICATIONS, LLC - MO 4932 LADUE MO
— 314-564 0–9 XXXall 10 · 4 holders which blocks → T-MOBILE USA, INC. 6529 LADUE MO
— 314-565 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ST LOUIS MO
— 314-567 not yet reported which blocks → SOUTHWESTERN BELL 9533 LADUE MO
— 314-568 none assigned yet which blocks → T-MOBILE USA, INC. 6529 CREVECOEUR MO
— 314-569 not yet reported which blocks → SOUTHWESTERN BELL 9533 LADUE MO
— 314-570 8XXX9XXX which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 KIRKWOOD MO
— 314-571 0XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 ST LOUIS MO
— 314-572 not yet reported which blocks → SOUTHWESTERN BELL 9533 ST LOUIS MO
— 314-574 none assigned yet which blocks → T-MOBILE USA, INC. 6529 ST LOUIS MO
— 314-575 none assigned yet which blocks → T-MOBILE USA, INC. 6529 CREVECOEUR MO
— 314-576 not yet reported which blocks → SOUTHWESTERN BELL 9533 CREVECOEUR MO
— 314-577 not yet reported which blocks → SOUTHWESTERN BELL 9533 ST LOUIS MO
— 314-578 8XXX9XXX which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 KIRKWOOD MO
— 314-579 3XXX which blocks → SOUTHWESTERN BELL 9533 CREVECOEUR MO
— 314-580 not yet reported which blocks → CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MO 5814 LADUE MO
— 314-581 none assigned yet which blocks → T-MOBILE USA, INC. 6529 CREVECOEUR MO
— 314-583 not yet reported which blocks → T-MOBILE USA, INC. 6529 ST LOUIS MO
— 314-584 0–9 XXXall 10 · 4 holders which blocks → ONVOY, LLC - MO 093F ST LOUIS MO
— 314-587 0XXX5XXX6XXX9XXX which blocks → SOUTHWESTERN BELL 9533 LADUE 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.