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 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
— 314-521 not yet reported which blocks → SOUTHWESTERN BELL 9533 LADUE MO
— 314-522 not yet reported which blocks → SOUTHWESTERN BELL 9533 LADUE MO
— 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
— 314-529 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
— 314-538 not yet reported which blocks → SOUTHWESTERN BELL 9533 LADUE MO
— 314-539 1XXX which blocks → SOUTHWESTERN BELL 9533 ST LOUIS 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
— 314-551 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
— 314-567 not yet reported which blocks → SOUTHWESTERN BELL 9533 LADUE MO
— 314-569 not yet reported which blocks → SOUTHWESTERN BELL 9533 LADUE 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
— 314-576 not yet reported which blocks → SOUTHWESTERN BELL 9533 CREVECOEUR MO
— 314-577 not yet reported which blocks → SOUTHWESTERN BELL 9533 ST LOUIS MO
— 314-579 3XXX which blocks → SOUTHWESTERN BELL 9533 CREVECOEUR MO
— 314-587 0XXX5XXX6XXX9XXX which blocks → SOUTHWESTERN BELL 9533 LADUE MO
— 314-588 not yet reported which blocks → SOUTHWESTERN BELL 9533 ST LOUIS MO
— 314-589 not yet reported which blocks → SOUTHWESTERN BELL 9533 ST LOUIS MO
— 314-592 not yet reported which blocks → SOUTHWESTERN BELL 9533 LADUE MO
— 314-595 not yet reported which blocks → SOUTHWESTERN BELL 9533 LADUE MO
— 314-601 1XXX2XXX3XXX4XXX5XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 ST LOUIS MO
— 314-612 0XXX4XXX9XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 ST LOUIS MO
— 314-613 not yet reported which blocks → SOUTHWESTERN BELL 9533 ST LOUIS MO
— 314-615 not yet reported which blocks → SOUTHWESTERN BELL 9533 ST LOUIS MO
— 314-621 not yet reported which blocks → SOUTHWESTERN BELL 9533 ST LOUIS MO
— 314-622 not yet reported which blocks → SOUTHWESTERN BELL 9533 ST LOUIS MO
— 314-628 0XXX1XXX7XXX8XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 CREVECOEUR MO
— 314-631 not yet reported which blocks → SOUTHWESTERN BELL 9533 ST LOUIS MO
— 314-632 6XXX which blocks → SOUTHWESTERN BELL 9533 ST LOUIS MO
— 314-633 not yet reported which blocks → SOUTHWESTERN BELL 9533 ST LOUIS MO
— 314-638 not yet reported which blocks → SOUTHWESTERN BELL 9533 ST LOUIS MO
— 314-641 1XXX4XXX6XXX9XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 ST LOUIS MO
— 314-644 8XXX which blocks → SOUTHWESTERN BELL 9533 ST LOUIS MO
— 314-645 not yet reported which blocks → SOUTHWESTERN BELL 9533 ST LOUIS MO
— 314-646 9XXX which blocks → SOUTHWESTERN BELL 9533 ST LOUIS MO
— 314-647 not yet reported which blocks → SOUTHWESTERN BELL 9533 ST LOUIS MO
— 314-652 3XXX which blocks → SOUTHWESTERN BELL 9533 ST LOUIS MO
— 314-653 not yet reported which blocks → SOUTHWESTERN BELL 9533 LADUE MO
— 314-654 not yet reported 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.