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 972
SOUTHWESTERN BELL 307
SOUTHWESTERN BELL TELEPHONE COMPANY - TX 17
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
— 972-547 not yet reported which blocks → SOUTHWESTERN BELL 9533 MCKINNEY TX
— 972-548 not yet reported which blocks → SOUTHWESTERN BELL 9533 MCKINNEY TX
— 972-551 4XXX9XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 TERRELL TX
— 972-552 0XXX4XXX6XXX7XXX8XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 FORNEY TX
— 972-556 5XXX which blocks → SOUTHWESTERN BELL 9533 DALLAS TX
— 972-557 not yet reported which blocks → SOUTHWESTERN BELL 9533 DALLAS TX
— 972-558 not yet reported which blocks → SOUTHWESTERN BELL 9533 GRANDPRARI TX
— 972-559 0XXX1XXX2XXX3XXX4XXX8XXX9XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 DALLAS TX
— 972-561 0XXX6XXX7XXX8XXX9XXX which blocks → SOUTHWESTERN BELL 9533 GRANDPRARI TX
— 972-562 not yet reported which blocks → SOUTHWESTERN BELL 9533 MCKINNEY TX
— 972-563 not yet reported which blocks → SOUTHWESTERN BELL 9533 TERRELL TX
— 972-564 8XXX which blocks → SOUTHWESTERN BELL 9533 FORNEY TX
— 972-566 not yet reported which blocks → SOUTHWESTERN BELL 9533 DALLAS TX
— 972-569 none assigned yet which blocks → SOUTHWESTERN BELL 9533 MCKINNEY TX
— 972-572 6XXX which blocks → SOUTHWESTERN BELL 9533 DALLAS TX
— 972-576 6XXX7XXX9XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 RED OAK TX
— 972-583 5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → SOUTHWESTERN BELL TELEPHONE COMPANY - TX 7726 PLANO TX
— 972-584 0XXX1XXX6XXX7XXX9XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 DALLAS TX
— 972-588 0XXX4XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 DALLAS TX
— 972-591 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 DALLAS TX
— 972-595 2XXX4XXX7XXX8XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 GRANDPRARI TX
— 972-601 not yet reported which blocks → SOUTHWESTERN BELL 9533 GRANDPRARI TX
— 972-602 5XXX which blocks → SOUTHWESTERN BELL 9533 GRANDPRARI TX
— 972-603 5XXX6XXX8XXX which blocks → SOUTHWESTERN BELL 9533 GRANDPRARI TX
— 972-606 not yet reported which blocks → SOUTHWESTERN BELL 9533 GRANDPRARI TX
— 972-610 not yet reported which blocks → SOUTHWESTERN BELL 9533 XXXXXXXXXX TX
— 972-613 3XXX which blocks → SOUTHWESTERN BELL 9533 DALLAS TX
— 972-614 6XXX which blocks → SOUTHWESTERN BELL 9533 GRANDPRARI TX
— 972-617 not yet reported which blocks → SOUTHWESTERN BELL 9533 RED OAK TX
— 972-620 not yet reported which blocks → SOUTHWESTERN BELL 9533 DALLAS TX
— 972-623 7XXX8XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 GRANDPRARI TX
— 972-624 6XXX7XXX9XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 FRISCO TX
— 972-625 not yet reported which blocks → SOUTHWESTERN BELL 9533 FRISCO TX
— 972-628 0XXX which blocks → SOUTHWESTERN BELL 9533 DALLAS TX
— 972-630 0XXX3XXX4XXX6XXX8XXX9XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 DALLAS TX
— 972-635 0XXX3XXX4XXX5XXX8XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 ROYSE CITY TX
— 972-636 1XXX4XXX5XXX6XXX8XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 ROYSE CITY TX
— 972-641 not yet reported which blocks → SOUTHWESTERN BELL 9533 GRANDPRARI TX
— 972-642 not yet reported which blocks → SOUTHWESTERN BELL 9533 GRANDPRARI TX
— 972-643 8XXX which blocks → SOUTHWESTERN BELL 9533 DALLAS TX
— 972-644 not yet reported which blocks → SOUTHWESTERN BELL 9533 DALLAS TX
— 972-647 not yet reported which blocks → SOUTHWESTERN BELL 9533 GRANDPRARI TX
— 972-660 not yet reported which blocks → SOUTHWESTERN BELL 9533 GRANDPRARI TX
— 972-661 not yet reported which blocks → SOUTHWESTERN BELL 9533 DALLAS TX
— 972-663 0XXX5XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 DALLAS TX
— 972-664 4XXX which blocks → SOUTHWESTERN BELL 9533 DALLAS TX
— 972-669 not yet reported which blocks → SOUTHWESTERN BELL 9533 DALLAS TX
— 972-671 1XXX3XXX4XXX9XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 DALLAS TX
— 972-673 9XXX which blocks → SOUTHWESTERN BELL TELEPHONE COMPANY - TX 7726 PLANO TX
— 972-680 not yet reported which blocks → SOUTHWESTERN BELL 9533 DALLAS TX

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.