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 580
SOUTHWESTERN BELL 157
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
— 580-591 none assigned yet which blocks → SOUTHWESTERN BELL 9533 LAWTON OK
— 580-595 none assigned yet which blocks → SOUTHWESTERN BELL 9533 LAWTON OK
— 580-596 0XXX4XXX5XXX6XXX7XXX8XXX9XXX · 7 holders which blocks → SOUTHWESTERN BELL 9533 CHEROKEE OK
— 580-628 4XXX8XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 TONKAWA OK
— 580-633 0XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 ELDORADO OK
— 580-648 0XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → SOUTHWESTERN BELL 9533 OLUSTEE OK
— 580-658 0XXX8XXX which blocks → SOUTHWESTERN BELL 9533 MARLOW OK
— 580-662 0XXX3XXX4XXX5XXX6XXX · 5 holders which blocks → SOUTHWESTERN BELL 9533 RINGLING OK
— 580-666 0XXX3XXX4XXX6XXX8XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 ROCKY OK
— 580-668 4XXX7XXX8XXX9XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 WILSON OK
— 580-669 0XXX3XXX5XXX6XXX7XXX9XXX · 6 holders which blocks → SOUTHWESTERN BELL 9533 GLENCOE OK
— 580-677 2XXX5XXX which blocks → SOUTHWESTERN BELL 9533 MADILL OK
— 580-718 6XXX9XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 PONCA CITY OK
— 580-723 0XXX2XXX3XXX7XXX8XXX · 5 holders which blocks → SOUTHWESTERN BELL 9533 RED ROCK OK
— 580-724 0XXX8XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 MORRISON OK
— 580-725 0XXX2XXX5XXX7XXX8XXX9XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 BILLINGS OK
— 580-726 0XXX9XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 HOBART OK
— 580-730 0XXX1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 LAWTON OK
— 580-738 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 7 holders which blocks → SOUTHWESTERN BELL 9533 HEADRICK OK
— 580-743 0XXX1XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 HUGO OK
— 580-745 0XXX1XXX4XXX5XXX6XXX8XXX · 5 holders which blocks → SOUTHWESTERN BELL 9533 DURANT OK
— 580-757 0XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → SOUTHWESTERN BELL 9533 RYAN OK
— 580-758 0XXX2XXX4XXX5XXX6XXX7XXX · 5 holders which blocks → SOUTHWESTERN BELL 9533 WAUKOMIS OK
— 580-759 0XXX4XXX7XXX9XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 STRATFORD OK
— 580-762 not yet reported which blocks → SOUTHWESTERN BELL 9533 PONCA CITY OK
— 580-763 none assigned yet which blocks → SOUTHWESTERN BELL 9533 PONCA CITY OK
— 580-765 not yet reported which blocks → SOUTHWESTERN BELL 9533 PONCA CITY OK
— 580-767 not yet reported which blocks → SOUTHWESTERN BELL 9533 PONCA CITY OK
— 580-772 8XXX which blocks → SOUTHWESTERN BELL 9533 WEATHERFD OK
— 580-774 none assigned yet which blocks → SOUTHWESTERN BELL 9533 WEATHERFD OK
— 580-782 4XXX6XXX8XXX9XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 MANGUM OK
— 580-795 none assigned yet which blocks → SOUTHWESTERN BELL 9533 MADILL OK
— 580-816 0XXX2XXX5XXX6XXX7XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 WEATHERFD OK
— 580-819 8XXX which blocks → SOUTHWESTERN BELL 9533 WEATHERFD OK
— 580-821 7XXX9XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 ELK CITY OK
— 580-832 0XXX6XXX7XXX8XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 CORDELL OK
— 580-846 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → SOUTHWESTERN BELL 9533 LONE WOLF OK
— 580-847 0XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → SOUTHWESTERN BELL 9533 BENNINGTON OK
— 580-855 4XXX5XXX8XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 CARRIER OK
— 580-857 0XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → SOUTHWESTERN BELL 9533 ALLEN OK
— 580-873 0XXX3XXX4XXX6XXX7XXX8XXX · 5 holders which blocks → SOUTHWESTERN BELL 9533 FORTTOWSON OK
— 580-874 0XXX3XXX8XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 KREMLIN OK
— 580-875 0XXX5XXX7XXX8XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 WALTERS OK
— 580-877 0XXX1XXX2XXX4XXX5XXX7XXX9XXX · 4 holders which blocks → SOUTHWESTERN BELL 9533 SOUTHMEADE OK
— 580-889 none assigned yet which blocks → SOUTHWESTERN BELL 9533 ATOKA OK
— 580-897 not yet reported which blocks → SOUTHWESTERN BELL 9533 XXXXXXXXXX OK
— 580-916 8XXX9XXX · 2 holders which blocks → SOUTHWESTERN BELL 9533 DURANT OK
— 580-920 none assigned yet which blocks → SOUTHWESTERN BELL 9533 DURANT OK
— 580-924 not yet reported which blocks → SOUTHWESTERN BELL 9533 DURANT OK
— 580-925 0XXX5XXX6XXX · 3 holders which blocks → SOUTHWESTERN BELL 9533 KONAWA OK

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.