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 210
SOUTHWESTERN BELL 281
NEW CINGULAR WIRELESS PCS, LLC - IL 129
T-MOBILE USA, INC. 94
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - TX 54
MCIMETRO ACCESS TRANSMISSION SERVICES LLC 39
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
— 210-521 not yet reported which blocks → SOUTHWESTERN BELL 9533 SANANTONIO TX
— 210-522 not yet reported which blocks → SOUTHWESTERN BELL 9533 SANANTONIO TX
— 210-523 9XXX which blocks → SOUTHWESTERN BELL 9533 SANANTONIO TX
— 210-524 not yet reported which blocks → SOUTHWESTERN BELL 9533 SANANTONIO TX
— 210-525 not yet reported which blocks → SOUTHWESTERN BELL 9533 SANANTONIO TX
— 210-527 0XXX3XXX4XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 SANANTONIO TX
— 210-528 0XXX1XXX8XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 SANANTONIO TX
— 210-530 1XXX4XXX8XXX which blocks → SOUTHWESTERN BELL 9533 SANANTONIO TX
— 210-531 6XXX which blocks → SOUTHWESTERN BELL 9533 SANANTONIO TX
— 210-532 not yet reported which blocks → SOUTHWESTERN BELL 9533 SANANTONIO TX
— 210-533 not yet reported which blocks → SOUTHWESTERN BELL 9533 SANANTONIO TX
— 210-534 not yet reported which blocks → SOUTHWESTERN BELL 9533 SANANTONIO TX
— 210-535 not yet reported which blocks → T-MOBILE USA, INC. 6529 SANANTONIO TX
— 210-536 not yet reported which blocks → TELEPORT COMMUNICATIONS AMERICA, LLC - TX 7138 SANANTONIO TX
— 210-538 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → PAETEC ITEL, LLC 829J SANANTONIO TX
— 210-541 2XXX4XXX5XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 SANANTONIO TX
— 210-543 1XXX which blocks → SOUTHWESTERN BELL 9533 SANANTONIO TX
— 210-545 not yet reported which blocks → SOUTHWESTERN BELL 9533 SANANTONIO TX
— 210-546 not yet reported which blocks → LEVEL 3 OF TELECOM OF TEXAS, LLC - TX 8434 SANANTONIO TX
— 210-547 6XXX7XXX8XXX9XXX · 3 holders which blocks → GRANDE COMMUNICATIONS NETWORKS, INC. - TX 7670 SANANTONIO TX
— 210-553 not yet reported which blocks → SPOK, INC. 6630 SANANTONIO TX
— 210-554 not yet reported which blocks → SOUTHWESTERN BELL 9533 SANANTONIO TX
— 210-555 not yet reported which blocks → MULTIPLE OCN LISTING MULT DIR ASST TX
— 210-558 not yet reported which blocks → SOUTHWESTERN BELL 9533 SANANTONIO TX
— 210-559 none assigned yet which blocks → T-MOBILE USA, INC. 6529 SANANTONIO TX
— 210-561 not yet reported which blocks → SOUTHWESTERN BELL 9533 SANANTONIO TX
— 210-562 0XXX3XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 SANANTONIO TX
— 210-564 4XXX5XXX7XXX9XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 SANANTONIO TX
— 210-565 not yet reported which blocks → SOUTHWESTERN BELL 9533 SANANTONIO TX
— 210-566 not yet reported which blocks → SOUTHWESTERN BELL 9533 SANANTONIO TX
— 210-567 not yet reported which blocks → SOUTHWESTERN BELL 9533 SANANTONIO TX
— 210-568 3XXX5XXX7XXX9XXX which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 SANANTONIO TX
— 210-572 not yet reported which blocks → LEVEL 3 OF TELECOM OF TEXAS, LLC - TX 8434 SANANTONIO TX
— 210-573 none assigned yet which blocks → T-MOBILE USA, INC. 6529 SANANTONIO TX
— 210-575 not yet reported which blocks → SOUTHWESTERN BELL 9533 SANANTONIO TX
— 210-576 0XXX1XXX2XXX4XXX6XXX8XXX9XXX · 5 holders which blocks → U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 671J SANANTONIO TX
— 210-579 3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 SANANTONIO TX
— 210-581 not yet reported which blocks → LEVEL 3 OF TELECOM OF TEXAS, LLC - TX 8434 SANANTONIO TX
— 210-582 not yet reported which blocks → LEVEL 3 OF TELECOM OF TEXAS, LLC - TX 8434 SANANTONIO TX
— 210-586 not yet reported which blocks → SOUTHWESTERN BELL 9533 SANANTONIO TX
— 210-587 5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → MCIMETRO ACCESS TRANSMISSION SERVICES LLC 7229 SANANTONIO TX
— 210-588 0XXX9XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 SANANTONIO TX
— 210-590 not yet reported which blocks → SOUTHWESTERN BELL 9533 SANANTONIO TX
— 210-592 1XXX3XXX4XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 SANANTONIO TX
— 210-593 3XXX6XXX7XXX8XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 SANANTONIO TX
— 210-595 0XXX1XXX3XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 SANANTONIO TX
— 210-599 not yet reported which blocks → SOUTHWESTERN BELL 9533 SANANTONIO TX
— 210-601 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 SANANTONIO TX
— 210-602 not yet reported which blocks → NEW CINGULAR WIRELESS PCS, LLC - IL 6534 SANANTONIO TX
— 210-603 not yet reported which blocks → SPOK, INC. 6630 SANANTONIO 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.